I need to get a cheap DVD player for a rental property. I have a
choice of a Philips or a Memorex DVD player for $24.99 USD. Anyone
have any thoughts/printable comments about which might be more
reliable?

Bob Hofmann

"hr(bob) " wrote in message
...
I need to get a cheap DVD player for a rental property. I have a
choice of a Philips or a Memorex DVD player for $24.99 USD. Anyone
have any thoughts/printable comments about which might be more
reliable?

Bob Hofmann

Personally Bob, I would go for the Philips, as it's at least likely to be
actually made by them. As Meat says, it's basically a disposable item, but
that doesn't help much when it fails 6 months in ... FWIW, most of the cheap
ones that I see for repair, have very 'marginal' power supplies in that they
have tiny 85 deg caps fitted that are rated about 2 volts above what they
have to work at, and it's often these that fail inside warranty. A
contributory factor in this, I think, is ventilation, so you might want to
consider keeping it out in the open, rather than tucking it away in a
cupboard underneath the TV.

Arfa

"Arfa Daily" wrote in message
...

"hr(bob) " wrote in message
...
I need to get a cheap DVD player for a rental property. I have a
choice of a Philips or a Memorex DVD player for $24.99 USD. Anyone
have any thoughts/printable comments about which might be more
reliable?

Bob Hofmann

Personally Bob, I would go for the Philips, as it's at least likely to be
actually made by them. As Meat says, it's basically a disposable item, but
that doesn't help much when it fails 6 months in ... FWIW, most of the
cheap ones that I see for repair, have very 'marginal' power supplies in
that they have tiny 85 deg caps fitted that are rated about 2 volts above
what they have to work at, and it's often these that fail inside warranty.
A contributory factor in this, I think, is ventilation, so you might want
to consider keeping it out in the open, rather than tucking it away in a
cupboard underneath the TV.

Arfa


Don't encourage Philips - they are the worst. That's my advice anyway.

Mark Z.

"Mark D. Zacharias" wrote in message
...

"Arfa Daily" wrote in message
...

"hr(bob) " wrote in message
...
I need to get a cheap DVD player for a rental property. I have a
choice of a Philips or a Memorex DVD player for $24.99 USD. Anyone
have any thoughts/printable comments about which might be more
reliable?

Bob Hofmann

Personally Bob, I would go for the Philips, as it's at least likely to be
actually made by them. As Meat says, it's basically a disposable item,
but that doesn't help much when it fails 6 months in ... FWIW, most of
the cheap ones that I see for repair, have very 'marginal' power supplies
in that they have tiny 85 deg caps fitted that are rated about 2 volts
above what they have to work at, and it's often these that fail inside
warranty. A contributory factor in this, I think, is ventilation, so you
might want to consider keeping it out in the open, rather than tucking it
away in a cupboard underneath the TV.

Arfa


Don't encourage Philips - they are the worst. That's my advice anyway.

Mark Z.


Hi Mark
Well, he's actually a bit between a rock and a hard place on this one,
because over here at least, and I guess it's probably the case there as
well, gear marketed under the Memorex name often is Philips inside anyway.

Although Philips stuff may not be the most pleasant to work on, and their
service info sucks, I have found it in general to be quite well built, and
reasonably reliable. Iam interested in what negative experiences you might
have had to make you feel that it is "the worst" ?? Do you feel that the
Memorex would be a better bet? We might be seeing a difference in products
here between the US and UK.

Arfa

On Nov 18, 7:03 pm, "Arfa Daily" wrote:
"Mark D. Zacharias" wrote in .. .







"Arfa Daily" wrote in message
...

"hr(bob) " wrote in message
...
I need to get a cheap DVD player for a rental property. I have a
choice of a Philips or a Memorex DVD player for $24.99 USD. Anyone
have any thoughts/printable comments about which might be more
reliable?

Bob Hofmann

Personally Bob, I would go for the Philips, as it's at least likely to be
actually made by them. As Meat says, it's basically a disposable item,
but that doesn't help much when it fails 6 months in ... FWIW, most of
the cheap ones that I see for repair, have very 'marginal' power supplies
in that they have tiny 85 deg caps fitted that are rated about 2 volts
above what they have to work at, and it's often these that fail inside
warranty. A contributory factor in this, I think, is ventilation, so you
might want to consider keeping it out in the open, rather than tucking it
away in a cupboard underneath the TV.

Arfa

Don't encourage Philips - they are the worst. That's my advice anyway.

Mark Z.

Hi Mark
Well, he's actually a bit between a rock and a hard place on this one,
because over here at least, and I guess it's probably the case there as
well, gear marketed under the Memorex name often is Philips inside anyway.

Although Philips stuff may not be the most pleasant to work on, and their
service info sucks, I have found it in general to be quite well built, and
reasonably reliable. Iam interested in what negative experiences you might
have had to make you feel that it is "the worst" ?? Do you feel that the
Memorex would be a better bet? We might be seeing a difference in products
here between the US and UK.

Arfa- Hide quoted text -

- Show quoted text -

I'll go to the stores that are advertising the players tomorrow
(Monday) and see if I can tell anything about who might actually make
them. It would really be interesting if they both turned out to be
the same unit with different labeling. Also, I want to see if either
one carries more than a 90 day warranty.

Bob Hofmann

In article
,
"hr(bob) " wrote:

I need to get a cheap DVD player for a rental property. I have a
choice of a Philips or a Memorex DVD player for $24.99 USD. Anyone
have any thoughts/printable comments about which might be more
reliable?

Bob Hofmann

How much is your time worth? Why not get something that will last longer
than three months, and save yourself the trouble of constantly replacing
it?

I need to get a cheap DVD player for a rental property. I have a
choice of a Philips or a Memorex DVD player for $24.99 USD. Anyone
have any thoughts/printable comments about which might be more
reliable?


It's a crapshoot, they're both junk, but either may do the job. I'd be
shocked if there's any appreciable difference in quality, there's a good
chance that inside they're identical units.

"hr(bob) " wrote:

I need to get a cheap DVD player for a rental property. I have a
choice of a Philips or a Memorex DVD player for $24.99 USD.

For that price expect junk only.

Graham

Meat Plow wrote:

On Sun, 18 Nov 2007 07:23:35 -0800, hr(bob) wrote:

I need to get a cheap DVD player for a rental property. I have a
choice of a Philips or a Memorex DVD player for $24.99 USD. Anyone
have any thoughts/printable comments about which might be more
reliable?

At that price it's basically a disposable unit. Sitting here on my desk is
an Oritron player.

A decent company.


One of those half sized units just wide enough for the
tray and a button or two. I have it hooked up to my Olevia 32" LCD via
component connection, what a picture for 480p. I've used this Oritron (who
knows who made it)

Oritron actually. I've even been to one of their factories. They were making DVD
players on the line at the time and they ship FOUR 40 foot containers of them
from that factory DAILY ! They're a BIG company.
http://www.oritron.com/

Graham

Arfa Daily wrote:

they have tiny 85 deg caps fitted that are rated about 2 volts above what they

have to work at

There's nothing wrong with that voltage rating. Why do you think they have a
working voltage rating ?

Graham

"Eeyore" wrote in message
...


Arfa Daily wrote:

they have tiny 85 deg caps fitted that are rated about 2 volts above what
they

have to work at

There's nothing wrong with that voltage rating. Why do you think they have
a
working voltage rating ?

Graham


We've had this conversation before Graham. As a service engineer, which you,
I think, are not, I can only go by experience. The caps which regularly
fail, are (most) always rated just a couple of volts above what they are
actually running at. Now I know full well that you believe this to be a
nonsense, but I'm sure that anyone else on here who is regularly involved in
actually repairing the stuff, will tell you the same. It might be some kind
of anomaly in your reckoning, or even not possible to your mind. That
doesn't alter the fact that it is true. It might just be a physical size
versus internal heat issue. I just don't know, but it is so, whether you
believe it or not.

Other than this, I don't want to get into the discussion, as it's not what
the thread is about, and the last thing we need is another one degenerating
into a ridiculous flame war, as you get madder and madder, and all the usual
suspects jump in to have a pop at you ...

Arfa

"Arfa Daily" wrote in message
...

"Eeyore" wrote in message
...


Arfa Daily wrote:

they have tiny 85 deg caps fitted that are rated about 2 volts above
what they

have to work at

There's nothing wrong with that voltage rating. Why do you think they
have a
working voltage rating ?

Graham


We've had this conversation before Graham. As a service engineer, which
you, I think, are not, I can only go by experience. The caps which
regularly fail, are (most) always rated just a couple of volts above what
they are actually running at. Now I know full well that you believe this
to be a nonsense, but I'm sure that anyone else on here who is regularly
involved in actually repairing the stuff, will tell you the same. It might
be some kind of anomaly in your reckoning, or even not possible to your
mind. That doesn't alter the fact that it is true. It might just be a
physical size versus internal heat issue. I just don't know, but it is so,
whether you believe it or not.

Other than this, I don't want to get into the discussion, as it's not what
the thread is about, and the last thing we need is another one
degenerating into a ridiculous flame war, as you get madder and madder,
and all the usual suspects jump in to have a pop at you ...

Arfa


Does the 2v headway allow for noise spikes. Tants often fail this way.

Regards

"Arfa Daily" wrote in message
...

"Mark D. Zacharias" wrote in message
...

"Arfa Daily" wrote in message
...

"hr(bob) " wrote in message
...
I need to get a cheap DVD player for a rental property. I have a
choice of a Philips or a Memorex DVD player for $24.99 USD. Anyone
have any thoughts/printable comments about which might be more
reliable?

Bob Hofmann

Personally Bob, I would go for the Philips, as it's at least likely to
be actually made by them. As Meat says, it's basically a disposable
item, but that doesn't help much when it fails 6 months in ... FWIW,
most of the cheap ones that I see for repair, have very 'marginal' power
supplies in that they have tiny 85 deg caps fitted that are rated about
2 volts above what they have to work at, and it's often these that fail
inside warranty. A contributory factor in this, I think, is ventilation,
so you might want to consider keeping it out in the open, rather than
tucking it away in a cupboard underneath the TV.

Arfa


Don't encourage Philips - they are the worst. That's my advice anyway.

Mark Z.


Hi Mark
Well, he's actually a bit between a rock and a hard place on this one,
because over here at least, and I guess it's probably the case there as
well, gear marketed under the Memorex name often is Philips inside anyway.

Although Philips stuff may not be the most pleasant to work on, and their
service info sucks, I have found it in general to be quite well built, and
reasonably reliable. Iam interested in what negative experiences you might
have had to make you feel that it is "the worst" ?? Do you feel that the
Memorex would be a better bet? We might be seeing a difference in products
here between the US and UK.

Arfa


Wow, Geoff. I'm not sure I have the mental energy to recount all of my
objections to Philips.
First of all I'm referring to Philips as they present here in the good 'ole
USA. They may be a much different company in your parts. I have seen some
evidence in past exchanges on the newsgroups that they use better quality
CRT's for example in their euro product.

1. Unusual physical manufacturing, often bordering on shoddy, even unsafe.
2. Expensive repair parts, then parts discontinued just about the time you
might need them. Example: I had a customer with an 8000.00 Philips data
projector, 4 years old and needing an LCD panel. Sorry, no longer available.
3. They have the worst phone service EVER.
4. They will not sell manuals etc unless you are one of their authorized
servicers.
5. Generally cannot buy individual mechanical parts for a DVD player for
example, only complete assemblies which cost two or three times (or more)
the retail price of the unit being repaired.
6. They have a well documented problem with paying consumer rebates. You can
spent months chasing your rebate, getting one stall tactic after another.

There was a web site called Planetfeedback.com . I think they have since
changed their name but Google ought to find it. If you query Philips you'll
find they get negative feedback like no other.


I worked on a Honeywell defibrillator made by Philips. The Euro metal fuse
holder contacts were so crusty with black oxidation that they would not even
conduct electricity to the body of the fuse they were in contact with.
Wouldn't want my life depending on that one...

End of rant (for now...)

Mark Z.

Terry wrote:

"Arfa Daily" wrote in message
"Eeyore" wrote in message
Arfa Daily wrote:

they have tiny 85 deg caps fitted that are rated about 2 volts above
what they

have to work at

There's nothing wrong with that voltage rating. Why do you think they
have a
working voltage rating ?


We've had this conversation before Graham. As a service engineer, which
you, I think, are not, I can only go by experience. The caps which
regularly fail, are (most) always rated just a couple of volts above what
they are actually running at. Now I know full well that you believe this
to be a nonsense, but I'm sure that anyone else on here who is regularly
involved in actually repairing the stuff, will tell you the same. It might
be some kind of anomaly in your reckoning, or even not possible to your
mind. That doesn't alter the fact that it is true. It might just be a
physical size versus internal heat issue. I just don't know, but it is so,
whether you believe it or not.

Other than this, I don't want to get into the discussion, as it's not what
the thread is about, and the last thing we need is another one
degenerating into a ridiculous flame war, as you get madder and madder,
and all the usual suspects jump in to have a pop at you ...


Does the 2v headway allow for noise spikes. Tants often fail this way.

Firstly you don't get much in the way of 'noise spikes' on a bulk reservoir
cap.

Secondly, tantalums have an entirely different chemistry which can even catch
fire or explode.

Lastly, the applied voltage on an electrolytic affects only the leakage current.
You can actually safely exceed the rated voltage of an electrolytic if you don't
care especailly about this by at least 10% without causing damage. I have done
this myself after taking careful advice from the manufacturer's agent when using
a 63V rated cap at around 69V in an amplifier under 'idle' conditions. FYI the
tech manager was keen to keep costs low. None of these ever exhibited early
failure problems.

Graham

"Mark D. Zacharias" wrote in message
. net...

"Arfa Daily" wrote in message
...

"Mark D. Zacharias" wrote in message
...

"Arfa Daily" wrote in message
...

"hr(bob) " wrote in message
...
I need to get a cheap DVD player for a rental property. I have a
choice of a Philips or a Memorex DVD player for $24.99 USD. Anyone
have any thoughts/printable comments about which might be more
reliable?

Bob Hofmann

Personally Bob, I would go for the Philips, as it's at least likely to
be actually made by them. As Meat says, it's basically a disposable
item, but that doesn't help much when it fails 6 months in ... FWIW,
most of the cheap ones that I see for repair, have very 'marginal'
power supplies in that they have tiny 85 deg caps fitted that are rated
about 2 volts above what they have to work at, and it's often these
that fail inside warranty. A contributory factor in this, I think, is
ventilation, so you might want to consider keeping it out in the open,
rather than tucking it away in a cupboard underneath the TV.

Arfa


Don't encourage Philips - they are the worst. That's my advice anyway.

Mark Z.


Hi Mark
Well, he's actually a bit between a rock and a hard place on this one,
because over here at least, and I guess it's probably the case there as
well, gear marketed under the Memorex name often is Philips inside
anyway.

Although Philips stuff may not be the most pleasant to work on, and their
service info sucks, I have found it in general to be quite well built,
and reasonably reliable. Iam interested in what negative experiences you
might have had to make you feel that it is "the worst" ?? Do you feel
that the Memorex would be a better bet? We might be seeing a difference
in products here between the US and UK.

Arfa


Wow, Geoff. I'm not sure I have the mental energy to recount all of my
objections to Philips.
First of all I'm referring to Philips as they present here in the good
'ole USA. They may be a much different company in your parts. I have seen
some evidence in past exchanges on the newsgroups that they use better
quality CRT's for example in their euro product.

1. Unusual physical manufacturing, often bordering on shoddy, even unsafe.
2. Expensive repair parts, then parts discontinued just about the time you
might need them. Example: I had a customer with an 8000.00 Philips data
projector, 4 years old and needing an LCD panel. Sorry, no longer
available.
3. They have the worst phone service EVER.
4. They will not sell manuals etc unless you are one of their authorized
servicers.
5. Generally cannot buy individual mechanical parts for a DVD player for
example, only complete assemblies which cost two or three times (or more)
the retail price of the unit being repaired.
6. They have a well documented problem with paying consumer rebates. You
can spent months chasing your rebate, getting one stall tactic after
another.

There was a web site called Planetfeedback.com . I think they have since
changed their name but Google ought to find it. If you query Philips
you'll find they get negative feedback like no other.


I worked on a Honeywell defibrillator made by Philips. The Euro metal fuse
holder contacts were so crusty with black oxidation that they would not
even conduct electricity to the body of the fuse they were in contact
with. Wouldn't want my life depending on that one...

End of rant (for now...)

Mark Z.

OK Mark. 'Nuff said ! I can't compete with that for positive experiences !

Arfa

Personally I avoid anything Philips, if I can.

"Eeyore" wrote in message
...


Terry wrote:

"Arfa Daily" wrote in message
"Eeyore" wrote in message
Arfa Daily wrote:

they have tiny 85 deg caps fitted that are rated about 2 volts above
what they

have to work at

There's nothing wrong with that voltage rating. Why do you think they
have a
working voltage rating ?


We've had this conversation before Graham. As a service engineer, which
you, I think, are not, I can only go by experience. The caps which
regularly fail, are (most) always rated just a couple of volts above
what
they are actually running at. Now I know full well that you believe
this
to be a nonsense, but I'm sure that anyone else on here who is
regularly
involved in actually repairing the stuff, will tell you the same. It
might
be some kind of anomaly in your reckoning, or even not possible to your
mind. That doesn't alter the fact that it is true. It might just be a
physical size versus internal heat issue. I just don't know, but it is
so,
whether you believe it or not.

Other than this, I don't want to get into the discussion, as it's not
what
the thread is about, and the last thing we need is another one
degenerating into a ridiculous flame war, as you get madder and madder,
and all the usual suspects jump in to have a pop at you ...


Does the 2v headway allow for noise spikes. Tants often fail this way.

Firstly you don't get much in the way of 'noise spikes' on a bulk
reservoir
cap.

Secondly, tantalums have an entirely different chemistry which can even
catch
fire or explode.

Lastly, the applied voltage on an electrolytic affects only the leakage
current.
You can actually safely exceed the rated voltage of an electrolytic if you
don't
care especailly about this by at least 10% without causing damage. I have
done
this myself after taking careful advice from the manufacturer's agent when
using
a 63V rated cap at around 69V in an amplifier under 'idle' conditions.
FYI the
tech manager was keen to keep costs low. None of these ever exhibited
early
failure problems.

Graham


Be careful exceeding the voltage rating of capacitors. It may be ok on the
batch
you tested but there are batch to batch variations. Experience has taught me
not
to trust manufacturers agents unless they put it in writing which they never
do of
course. Bulk resevoir caps need a 0.1uf in parallel or there will be noise
due to the inductance
of large caps.

I hope I am not teaching my grandmother 'how to suck eggs' :-)


Regards

"Thomas Tornblom" wrote in message
...
Personally I avoid anything Philips, if I can.

Agreed.

Terry wrote:
"Thomas Tornblom" wrote in message
...
Personally I avoid anything Philips, if I can.

Agreed.


I also have to agree, Philips have some odd ways of doing things.

Ron(UK)

"Terry" hath wroth:

Does the 2v headway allow for noise spikes. Tants often fail this way.

Tantalums are quite different. Exceed the voltage specification and
they catch fire and burn. It's quite impressive. You can accellerate
the process by reversing the voltage across the tantalum. Try it.
Just take a random small tanatalum and put it across a power supply.
First, it starts to get hot. Then it glows red. Finally, it bursts
into flames and spews toxic smoke. It does take a while to break
down. I've had the polarity reversed for perhaps 3 hours before it
flamed out.

The 2V headway is not for noise spikes. It's to derate the capacitor
voltage specification at high temperatures to extend the lifetime.

Reliability of Capacitors
http://www.illinoiscapacitor.com/uploads/papers_application/85560DAA867C4AE2871F2EFA1749A6C7.pdf

http://www.illinoiscapacitor.com/techcenter/lifecalculators.asp
The upper calculator is for electrolytics.

The primary cause of short lifetime is temperature (and self heating),
but insufficient voltage derating is a close second. Note that at
rated voltage and temperature, the lifetime of an electrolytic is
specified at either 1,000 or 10,000 hrs, depending on service type.
That's not very long. The designed is expected to derate the applied
voltage and operating temperature in order to extend the lifetime. A
2:1 derating will be good for a lifetime of about 15 years. A 2v out
of perhaps 15v derating, might be good enough to barely make it
through the warranty period.



--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

We've had this conversation before Graham. As a service engineer, which
you, I think, are not, I can only go by experience. The caps which
regularly fail, are (most) always rated just a couple of volts above what
they are actually running at. Now I know full well that you believe this
to be a nonsense, but I'm sure that anyone else on here who is regularly
involved in actually repairing the stuff, will tell you the same. It might
be some kind of anomaly in your reckoning, or even not possible to your
mind. That doesn't alter the fact that it is true. It might just be a
physical size versus internal heat issue. I just don't know, but it is so,
whether you believe it or not.

Other than this, I don't want to get into the discussion, as it's not what
the thread is about, and the last thing we need is another one
degenerating into a ridiculous flame war, as you get madder and madder,
and all the usual suspects jump in to have a pop at you ...



Second that, I haven't seen much from that guy aside from inflamatory flame
posts.

The voltage rating on capacitors is the voltage they'll tolerate without
popping, it's common design convention to add a safety margin of 50%, any
electrical engineer will tell you that. I've noticed a disturbing trend
lately of squeezing that margin smaller and smaller, along with
correspondingly more capacitor failures. It's not as bad as the faulty
electrolyte epidemic several years ago, but I find myself replacing a LOT
more electrolytics in modern equipment than stuff built back in the 80s and
90s.

"James Sweet" wrote in message
news:Ldk0j.7690$B21.1714@trndny07...


We've had this conversation before Graham. As a service engineer, which
you, I think, are not, I can only go by experience. The caps which
regularly fail, are (most) always rated just a couple of volts above what
they are actually running at. Now I know full well that you believe this
to be a nonsense, but I'm sure that anyone else on here who is regularly
involved in actually repairing the stuff, will tell you the same. It
might be some kind of anomaly in your reckoning, or even not possible to
your mind. That doesn't alter the fact that it is true. It might just be
a physical size versus internal heat issue. I just don't know, but it is
so, whether you believe it or not.

Other than this, I don't want to get into the discussion, as it's not
what the thread is about, and the last thing we need is another one
degenerating into a ridiculous flame war, as you get madder and madder,
and all the usual suspects jump in to have a pop at you ...



Second that, I haven't seen much from that guy aside from inflamatory
flame posts.

The voltage rating on capacitors is the voltage they'll tolerate without
popping, it's common design convention to add a safety margin of 50%, any
electrical engineer will tell you that. I've noticed a disturbing trend
lately of squeezing that margin smaller and smaller, along with
correspondingly more capacitor failures. It's not as bad as the faulty
electrolyte epidemic several years ago, but I find myself replacing a LOT
more electrolytics in modern equipment than stuff built back in the 80s
and 90s.

Jeff and James.
Thank you gentlemen. I feel vindicated ...

Arfa

"Ron(UK)" wrote in message
...
Terry wrote:
"Thomas Tornblom" wrote in message
...
Personally I avoid anything Philips, if I can.

Agreed.


I also have to agree, Philips have some odd ways of doing things.

Ron(UK)

I'll second that, Ron. But back on the original point of reliability, have
you ever had cause here in the UK to consider Philips gear to be
particularly badly built, or unreliable in any way, compared to other makes
? I wouldn't say that I actually have, certainly not to the point that Mark
Z and other US posters seem to have done. Perhaps there is some fundamental
difference between Philips products for the US market, and those for the
European market, given that Philips is fundamentally a European company,
being based in Holland. Interesting ...

Arfa

Arfa Daily wrote:
"Ron(UK)" wrote in message
...
Terry wrote:
"Thomas Tornblom" wrote in message
...
Personally I avoid anything Philips, if I can.
Agreed.


I also have to agree, Philips have some odd ways of doing things.

Ron(UK)

I'll second that, Ron. But back on the original point of reliability, have
you ever had cause here in the UK to consider Philips gear to be
particularly badly built, or unreliable in any way, compared to other makes
? I wouldn't say that I actually have, certainly not to the point that Mark
Z and other US posters seem to have done. Perhaps there is some fundamental
difference between Philips products for the US market, and those for the
European market, given that Philips is fundamentally a European company,
being based in Holland. Interesting ...

Arfa


I'm only going off the newer stuff. maybe that`s not as well put
together as the older gear.

I spent many years repairing vcrs, audio, and microwave ovens made by
Philips.

As I`m sure you know, they used a totally unique system in their later
video recorder transport, fairly reliable, heads wore out fast, but the
majority of problems were 'casebook' so a good little earner there.

Philips microwave ovens were good, again unconventional in some ways and
prone to recurring faults, so again a money spinner... erm.. I'm
starting to like Philips gear, it`s made me a few bob over the years!

I was never a fan of their 'moving coil' cd player mechanism, but I
guess it was early days for the technology.

Philips washers and dryers were jolly good for business in their way,
plenty of easy stock faults and easy availability of spares. another
bunce earner

So, lemme see, recently gone to the great landfill in the sky are a
Philips freeview receiver B.E.R due to some logic problem (again I
understand this is a well know fault but non the less unrepairable),
a just out of guarantee Philips DVD/Hard/Disk recorder - something in
the logic failed + DVD drive up the spout, such a clunker of a machine
anyway I wouldn`t spend any time trying to fix it.

Both those were my own equipment.

Also there were several DVD drives out of computers - I realise that
these probably weren`t made in the Philips factory, but they carry the
Philips brand name, and that`s what counts to the punter.

Anyhoo, I declared that I wouldn`t buy any Philips branded gear again,
and so far I`ve stuck to that.

Maybe I`m being unfair to Philips equipment, I dunno, the Philips stuff
I bought in the last few years has already gone to the tip and I have no
confidence in their products now. I imagine most of it is made in China?


Ron(UK)

On Nov 18, 11:50 pm, Smitty Two wrote:
In article
,
"hr(bob) " wrote:

I need to get a cheap DVD player for a rental property. I have a
choice of a Philips or a Memorex DVD player for $24.99 USD. Anyone
have any thoughts/printable comments about which might be more
reliable?

Bob Hofmann

How much is your time worth? Why not get something that will last longer
than three months, and save yourself the trouble of constantly replacing
it?

OK - Which brand(s) woukld you recommmend??

Bob Hofmann

On Mon, 19 Nov 2007 01:03:41 GMT, "Arfa Daily"
wrote:



Although Philips stuff may not be the most pleasant to work on, and their
service info sucks, I have found it in general to be quite well built, and
reasonably reliable. Iam interested in what negative experiences you might
have had to make you feel that it is "the worst" ?? Do you feel that the
Memorex would be a better bet? We might be seeing a difference in products
here between the US and UK.

Arfa


I used to have a recent Philips DVD player and it was not made by
Philips. The quality of the boards and components was similar to a $9
clock radio. There were also lots of firmware bugs which made it
almost unusable (and there were no updates available). When I got
tired of it I ended up throwing it away rather than donating it (I
didn't want anyone else to waste money of it).

Andy Cuffe

"Arfa Daily" hath wroth:

Jeff and James.
Thank you gentlemen. I feel vindicated ...

Personally, I feel vindictive. Time to rant some more on the topic of
reliable products.

Once upon a time, I was doing design reviews for a manufacturer of
consumer electronics. For those not familiar with the term "design
review", it's an ordeal process, where an outside authority is paid to
shoot holes in a pre-production design, with the specific purpose of
finding screwups, catching oversights, reducing costs, and generally
making the life of the designers miserable.

State of the art in component selection and computer modeling had
progressed to the point where it is possible to predict component
failure rates given known operating conditions. The capacitor
formulas at:
http://www.illinoiscapacitor.com/techcenter/lifecalculators.asp
are what is used. Note that the lifetime for electrolytics operating
at maximum ratings is only about 1000 hrs:
http://www.illinoiscapacitor.com/products/aluminum.asp

There are similar models for semiconductors based on thermal cycles
and power components based on simple entropy. Given years of
experience with a war chest of standard components, additional data
can be added to the mix.

My part of the puzzle wasn't in the failure prediction department, but
I watched the process evolve over the years. At one point, the
manufactory could estimate the point at which the largest number of
field failures would occur and target their stocking, warranties, and
replacement products accordingly. For example, if the calculations
showed that units sold on introduction will begin to fail after 3
years, then the warranty will be less than 3 years, and a replacement
product will be available at the 3 year mark. Under ideal
circumstances, everything will fail at once. This method gets the
product closer to this ideal.

In grinding the numbers, a simple spreadsheet was used for capacitors.
I may have a copy somewhere but don't want to leak someone else's
work. If I get ambitious, I'll recreate it. Anyway, the result is an
estimate of capacitor lifetime based on known operating conditions. If
the target lifetime is 3 years (26,000 hrs), then any capacitor that
shows a calculated longer lifetime is considered over-rated and is a
potential waste of valuable pennies to the bean counters. Once
identified, the size and voltage ratings are reduced downwards to fit
the predicted lifetimes.

In the distant past, there was an advantage to using as many
capacitors of the same exact value as possible to increase quantity
discounts and reduce handling overhead. With bulk lot purchasing and
robot assembly, this is no longer the case. It's perfectly acceptable
to have a wide variety of electrolytic sizes, values, and voltages
without impacting the cost. The result are boards stuffed with 3v,
4v, 6.3v, 8v, 10v, 12v, 15v, 16v, 18v, 25v, etc capacitors with almost
identical capacitance values. Such boards are easy to spot and should
give you a clue as to the degree of penny pinching that was required
to cut costs. If you have a product on the bench to repair and a wide
assortment of capacitors are apparently dead, don't assume user abuse.
It might be that they were sized specifically to all fail
simultaneously.

Anyway, I don't have much experience fixing DVD players or with
Philips products. I do have a Philips DVDR 995 DVD recorder, which
trashes most DVD-R's it tried to burn, and now refuses to play other
home burned DVD's, although it will play most commercial DVD's.
Probably a dying laser. It also has a rather oddly designed remote
control that also eats batteries. It was given to me with the warning
"It's crap" which I have personally verified. It would be at the
local thrift shop or recyclers were it not at the very bottom of my
equipment pile and therefore difficult to extract. Caveat Emptor.




--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

"hr(bob) " hath wroth:

On Nov 18, 11:50 pm, Smitty Two wrote:
In article
,
"hr(bob) " wrote:

I need to get a cheap DVD player for a rental property. I have a
choice of a Philips or a Memorex DVD player for $24.99 USD. Anyone
have any thoughts/printable comments about which might be more
reliable?

Bob Hofmann

How much is your time worth? Why not get something that will last longer
than three months, and save yourself the trouble of constantly replacing
it?

OK - Which brand(s) woukld you recommmend??
Bob Hofmann

Bad question. At that price level, even the so called name brand
manufacturers do not make their own products. They buy container
loads of product from Chinese vendors, and put their name on the
product. If really ambitious, they might document it, but normally,
all they do is stuff the white box into an impressive and gaudy retail
package. It's sometime difficult to contact the manufacturer or get
them to admit they imported the product.

The result is that you never know what you're getting. The quality
varies from dismal to impressive. I bought a no-name DVD player at
Kmart as a present. I think I paid $35 for it 3 years ago. It was a
gift for a 12 year old brat with a marked tendency to destroy
everything he touches. It's still working perfectly today, although
I've rebuilt the remote control twice. On the other hand, one of my
customers was giving presentations at Rotary Club meetings. I
convinced him that using a laptop for playing a short DVD movie was
overkill, and had him buy a DVD player. It was a Magnavox which
lasted about 60 days and died. The warranty was 30 days.

If you want to do the necessary research, it's possible to get a clue
as to the quality by looking at the guts on the FCC ID web pile. Look
at the serial number tag and extract the FCC ID number. Then go unto:
https://fjallfoss.fcc.gov/oetcf/eas/reports/GenericSearch.cfm
and find the listing. You may have to play with the format of the
"product code" as some entries start with a "-" or space. The inside
photos should give you a clue as to what you're buying. If it looks
like junk components, get something else.

If you insist on shopping by brand, I've had good luck with Panasonic
and Toshiba. However, there's no guarantee that they didn't just
stick their name on some piece of white box junk. At the bottom of
the barrel, I've had a history of weird problems with Sony. Sorry,
but not much experience with anything else.

Drivel: Do you supply a DVD player for your tenants? When I had my
rental, I wouldn't even give them the time of day, much less a free
DVD player. For a rental, anything will suffice, preferably the
cheapest, since it's assume they'll either destroy or steal it.

Drivel 2.0: No change on the local solar powered RFI generator front
because everyone is too busy to do anything useful. Sigh.


--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

On Nov 19, 7:27 pm, "Arfa Daily" wrote:
I'll second that, Ron. But back on the original point of reliability, have
you ever had cause here in the UK to consider Philips gear to be
particularly badly built, or unreliable in any way, compared to other makes

it varies, but in terms of reliability over the last few years there
have been numerous widespread problems (albeit in a narrow range of
stuff.)
-faulty tubes: W56ECK001X04, (chassis L01.1E) W66ECK001X14, etc.
-painter chips: chassis, A10 /E
-dvd recorder pickups dropping like flies (in most other and cheaper
makes i find the power supplies to go first!)

all of which are serious expensive problems which can mean a write
off. Not funny in such new equipment.

Apart from that though, I usually find the build quality to be pretty
good. I personally still have a 16 year old 28GR9772 working superbly
in the bedroom and a VR632 which has only had the usual minor plastic
cog problem as with most turbo decks. Most of the Philips Tvs I get
asked to repair apart from the above listed known 'dogs' are still
serviceable, even the likes of CP90 and CP110. but I digress.

to get back on topic to the dvd discussion, I would stick with the
philips being a more well known name, but must echo what others have
said, i.e. at that price point you're going to get cheap and nasty
stuff in any case. You get what you pay for. Anyone worried about
reliability would be well advised just to skip that price bracket.

-B

"Andy Cuffe" wrote in message
...
On Mon, 19 Nov 2007 01:03:41 GMT, "Arfa Daily"
wrote:



Although Philips stuff may not be the most pleasant to work on, and their
service info sucks, I have found it in general to be quite well built, and
reasonably reliable. Iam interested in what negative experiences you might
have had to make you feel that it is "the worst" ?? Do you feel that the
Memorex would be a better bet? We might be seeing a difference in products
here between the US and UK.

Arfa


I used to have a recent Philips DVD player and it was not made by
Philips. The quality of the boards and components was similar to a $9
clock radio. There were also lots of firmware bugs which made it
almost unusable (and there were no updates available). When I got
tired of it I ended up throwing it away rather than donating it (I
didn't want anyone else to waste money of it).

Andy Cuffe

That's interesting Andy. I see a reasonable amount of Philips stuff - mainly
hifi and DVD - and I can't recall ever seeing an item that you would not
have said was actually made by them. They have a distinct 'Philips-ness'
about them, and it would be very easy to say, when taking one to bits, "that
doesn't look like a Philips ..." if indeed it didn't. So perhaps they do
reserve stuff that they make themselves for the 'home' market, and badge
stuff of other manufacture, for the US market. I suppose it could be
something to do with import restrictions or duties or even for some
'political' reason. I have a friend who works for a company that carry out
exclusively Philips service. I'll give him a call, and see if they see stuff
that isn't of native Philips manufacture.

Arfa

"Jeff Liebermann" wrote in message
...
"Arfa Daily" hath wroth:

Jeff and James.
Thank you gentlemen. I feel vindicated ...

Personally, I feel vindictive. Time to rant some more on the topic of
reliable products.

Once upon a time, I was doing design reviews for a manufacturer of
consumer electronics. For those not familiar with the term "design
review", it's an ordeal process, where an outside authority is paid to
shoot holes in a pre-production design, with the specific purpose of
finding screwups, catching oversights, reducing costs, and generally
making the life of the designers miserable.

State of the art in component selection and computer modeling had
progressed to the point where it is possible to predict component
failure rates given known operating conditions. The capacitor
formulas at:
http://www.illinoiscapacitor.com/techcenter/lifecalculators.asp
are what is used. Note that the lifetime for electrolytics operating
at maximum ratings is only about 1000 hrs:
http://www.illinoiscapacitor.com/products/aluminum.asp

There are similar models for semiconductors based on thermal cycles
and power components based on simple entropy. Given years of
experience with a war chest of standard components, additional data
can be added to the mix.

My part of the puzzle wasn't in the failure prediction department, but
I watched the process evolve over the years. At one point, the
manufactory could estimate the point at which the largest number of
field failures would occur and target their stocking, warranties, and
replacement products accordingly. For example, if the calculations
showed that units sold on introduction will begin to fail after 3
years, then the warranty will be less than 3 years, and a replacement
product will be available at the 3 year mark. Under ideal
circumstances, everything will fail at once. This method gets the
product closer to this ideal.

In grinding the numbers, a simple spreadsheet was used for capacitors.
I may have a copy somewhere but don't want to leak someone else's
work. If I get ambitious, I'll recreate it. Anyway, the result is an
estimate of capacitor lifetime based on known operating conditions. If
the target lifetime is 3 years (26,000 hrs), then any capacitor that
shows a calculated longer lifetime is considered over-rated and is a
potential waste of valuable pennies to the bean counters. Once
identified, the size and voltage ratings are reduced downwards to fit
the predicted lifetimes.

In the distant past, there was an advantage to using as many
capacitors of the same exact value as possible to increase quantity
discounts and reduce handling overhead. With bulk lot purchasing and
robot assembly, this is no longer the case. It's perfectly acceptable
to have a wide variety of electrolytic sizes, values, and voltages
without impacting the cost. The result are boards stuffed with 3v,
4v, 6.3v, 8v, 10v, 12v, 15v, 16v, 18v, 25v, etc capacitors with almost
identical capacitance values. Such boards are easy to spot and should
give you a clue as to the degree of penny pinching that was required
to cut costs. If you have a product on the bench to repair and a wide
assortment of capacitors are apparently dead, don't assume user abuse.
It might be that they were sized specifically to all fail
simultaneously.

Anyway, I don't have much experience fixing DVD players or with
Philips products. I do have a Philips DVDR 995 DVD recorder, which
trashes most DVD-R's it tried to burn, and now refuses to play other
home burned DVD's, although it will play most commercial DVD's.
Probably a dying laser. It also has a rather oddly designed remote
control that also eats batteries. It was given to me with the warning
"It's crap" which I have personally verified. It would be at the
local thrift shop or recyclers were it not at the very bottom of my
equipment pile and therefore difficult to extract. Caveat Emptor.



That's highly enlightening, and goes a long way to explaining the multiple
failures of caps that I often experience. It also answers for Graham, as to
why he is wrong with his contention that a cap can be run to its voltage
limit, with no ill effects. It also explains why you are absolutely spot on
about different voltage ratings of caps with the same values in the same
equipment. I have come across this many times and wondered why, when they
were using a 25v cap in one position, they then used a 16v one of the same
value elsewhere, even though the physical sizes are similar, and you would
have imagined that they could have got a better deal by buying twice as many
of a single type. Good stuff.

Arfa

On Nov 19, 7:30 pm, "Arfa Daily" wrote:
"Jeff Liebermann" wrote in message

...





"Arfa Daily" hath wroth:

Jeff and James.
Thank you gentlemen. I feel vindicated ...

Personally, I feel vindictive. Time to rant some more on the topic of
reliable products.

Once upon a time, I was doing design reviews for a manufacturer of
consumer electronics. For those not familiar with the term "design
review", it's an ordeal process, where an outside authority is paid to
shoot holes in a pre-production design, with the specific purpose of
finding screwups, catching oversights, reducing costs, and generally
making the life of the designers miserable.

State of the art in component selection and computer modeling had
progressed to the point where it is possible to predict component
failure rates given known operating conditions. The capacitor
formulas at:
http://www.illinoiscapacitor.com/techcenter/lifecalculators.asp
are what is used. Note that the lifetime for electrolytics operating
at maximum ratings is only about 1000 hrs:
http://www.illinoiscapacitor.com/products/aluminum.asp

There are similar models for semiconductors based on thermal cycles
and power components based on simple entropy. Given years of
experience with a war chest of standard components, additional data
can be added to the mix.

My part of the puzzle wasn't in the failure prediction department, but
I watched the process evolve over the years. At one point, the
manufactory could estimate the point at which the largest number of
field failures would occur and target their stocking, warranties, and
replacement products accordingly. For example, if the calculations
showed that units sold on introduction will begin to fail after 3
years, then the warranty will be less than 3 years, and a replacement
product will be available at the 3 year mark. Under ideal
circumstances, everything will fail at once. This method gets the
product closer to this ideal.

In grinding the numbers, a simple spreadsheet was used for capacitors.
I may have a copy somewhere but don't want to leak someone else's
work. If I get ambitious, I'll recreate it. Anyway, the result is an
estimate of capacitor lifetime based on known operating conditions. If
the target lifetime is 3 years (26,000 hrs), then any capacitor that
shows a calculated longer lifetime is considered over-rated and is a
potential waste of valuable pennies to the bean counters. Once
identified, the size and voltage ratings are reduced downwards to fit
the predicted lifetimes.

In the distant past, there was an advantage to using as many
capacitors of the same exact value as possible to increase quantity
discounts and reduce handling overhead. With bulk lot purchasing and
robot assembly, this is no longer the case. It's perfectly acceptable
to have a wide variety of electrolytic sizes, values, and voltages
without impacting the cost. The result are boards stuffed with 3v,
4v, 6.3v, 8v, 10v, 12v, 15v, 16v, 18v, 25v, etc capacitors with almost
identical capacitance values. Such boards are easy to spot and should
give you a clue as to the degree of penny pinching that was required
to cut costs. If you have a product on the bench to repair and a wide
assortment of capacitors are apparently dead, don't assume user abuse.
It might be that they were sized specifically to all fail
simultaneously.

Anyway, I don't have much experience fixing DVD players or with
Philips products. I do have a Philips DVDR 995 DVD recorder, which
trashes most DVD-R's it tried to burn, and now refuses to play other
home burned DVD's, although it will play most commercial DVD's.
Probably a dying laser. It also has a rather oddly designed remote
control that also eats batteries. It was given to me with the warning
"It's crap" which I have personally verified. It would be at the
local thrift shop or recyclers were it not at the very bottom of my
equipment pile and therefore difficult to extract. Caveat Emptor.

That's highly enlightening, and goes a long way to explaining the multiple
failures of caps that I often experience. It also answers for Graham, as to
why he is wrong with his contention that a cap can be run to its voltage
limit, with no ill effects. It also explains why you are absolutely spot on
about different voltage ratings of caps with the same values in the same
equipment. I have come across this many times and wondered why, when they
were using a 25v cap in one position, they then used a 16v one of the same
value elsewhere, even though the physical sizes are similar, and you would
have imagined that they could have got a better deal by buying twice as many
of a single type. Good stuff.

Arfa- Hide quoted text -

- Show quoted text -

Well, I looked at a couple of units and decided to go with the Philips
dvd player, since it had a 1-yr warranty on parts and labor and the
competition only had 90 days parts and labor. Brought it home and
hooked it up, actually followed some fairly clear instructions just to
see how good they were. Must have been written by someone with
English as a first language, because the English actually made sense,
without the usual stilted words. Turned it on and it worked just
fine.

Decided to use my older dvd at the rental and keep the new one here at
my home. BTW, the rental unit is only loaned out to ski friends who
don't trash it if they want to be allowed to rent it again. So I
don't worrry about problems with tenants like I would if it were a
regular ski rental.

Thanks for all the civil discussion this generated.

H. R.(Bob) Hofmann

snip

Brought it home and
hooked it up, actually followed some fairly clear instructions just to
see how good they were. Must have been written by someone with
English as a first language, because the English actually made sense,
without the usual stilted words.

snip

Philips are actually a Dutch company, so that's probably where the manual
originated. Interestingly though, the Dutch people speak English almost as
well as English people. I can easily work most of the near-European
countries on the radio, and it is always a pleasure to speak to the Dutch,
as they understand colloquial English and jokes just as any native English
speaker would. OTOH, if speaking to a German or French or Belgian ham for
instance, although they speak very good English - certainly much better than
I could speak their languages - I always find it necessary to keep it very
straightforward and 'text book'.

I once saw something that explained this as being to do with their proximity
to England, and their low-lying land, combining to give them good TV
coverage on UHF from south coast UK TV transmitters, so they grow up
watching UK / American TV as a 'free' supplement to their own. Is that just
the best example ever of a whole country being influenced by the power of TV
? I wonder if their ability to speak better English than their neighbours,
will decline when it all goes totally digital, and only the low power
transmitters are left here, which will probably struggle to make the trip to
Holland ?

Arfa

I believe a big factor is having TV with subtitles instead of dubbing.

I think this is true for most smaller countries.

On Mon, 19 Nov 2007 09:37:33 -0800 Jeff Liebermann
wrote in Message id: :


Tantalums are quite different. Exceed the voltage specification and
they catch fire and burn. It's quite impressive. You can accellerate
the process by reversing the voltage across the tantalum. Try it.
Just take a random small tanatalum and put it across a power supply.
First, it starts to get hot. Then it glows red. Finally, it bursts
into flames and spews toxic smoke. It does take a while to break
down. I've had the polarity reversed for perhaps 3 hours before it
flamed out.

Hell, a few or ten years ago we had actually shipped product where the
polarity on the silkscreen was incorrect, causing the tantalum caps to be
installed backwards. Some of the boards ran 24/7 for 3 to 4 months of
operation before catching fire.

On Mon, 19 Nov 2007 18:03:23 GMT "James Sweet"
wrote in Message id: Ldk0j.7690$B21.1714@trndny07:



We've had this conversation before Graham. As a service engineer, which
you, I think, are not, I can only go by experience. The caps which
regularly fail, are (most) always rated just a couple of volts above what
they are actually running at. Now I know full well that you believe this
to be a nonsense, but I'm sure that anyone else on here who is regularly
involved in actually repairing the stuff, will tell you the same. It might
be some kind of anomaly in your reckoning, or even not possible to your
mind. That doesn't alter the fact that it is true. It might just be a
physical size versus internal heat issue. I just don't know, but it is so,
whether you believe it or not.

Other than this, I don't want to get into the discussion, as it's not what
the thread is about, and the last thing we need is another one
degenerating into a ridiculous flame war, as you get madder and madder,
and all the usual suspects jump in to have a pop at you ...



Second that,

Thirded. I've been repairing electronics equipment for 20+ years.

I haven't seen much from that guy aside from inflamatory flame
posts.

And ditto as well. I was once looking for a source on power cords for some
vintage HP test equipment. The guy pops into the thread ranting and
screaming at me about how different types of wire would not effect the
quality of sound from a stereo system. Sheesh.

JW hath wroth:

On Mon, 19 Nov 2007 09:37:33 -0800 Jeff Liebermann
wrote in Message id: :


Tantalums are quite different. Exceed the voltage specification and
they catch fire and burn. It's quite impressive. You can accellerate
the process by reversing the voltage across the tantalum. Try it.
Just take a random small tanatalum and put it across a power supply.
First, it starts to get hot. Then it glows red. Finally, it bursts
into flames and spews toxic smoke. It does take a while to break
down. I've had the polarity reversed for perhaps 3 hours before it
flamed out.

Hell, a few or ten years ago we had actually shipped product where the
polarity on the silkscreen was incorrect, causing the tantalum caps to be
installed backwards. Some of the boards ran 24/7 for 3 to 4 months of
operation before catching fire.

I had a similar experience. Ancient IBM XT clone motherboard with a
few tanatalums backwards on the 5V power supply bus. The board worked
just fine for about a month of daily use. Then, I get a panic phone
call. "The computer is on fire. What do I do"? After careful
consideration of the situation for perhaps 100 milliseconds, I calmly
suggest they turn it off. I heard the loud "clunk" of the XT power
supply switch over the phone.

When I arrived, the culprit was obvious. There was a smoldering black
carbonized blob of charcoal where the tantalum should have been. I
couldn't resist applying power and watching it glow very bright red
and belch smoke. Was going to show everyone in the office the smoking
capacitor, but nobody seemed interested. So, I just cut it out of the
circuit board. I also looked around for more backwards capacitors,
but didn't find any. I don't recall if the silk screen was correct.
Incidentally, these were 10uf 15v caps on a 5v bus.

Later, I was curious if backwards tantalums could be thermally
detected. I applied reverse voltage and waited for the capacitor to
get hot. I had to apply more than the rated voltage to get it to
start heating. However, once it started to draw current and get warm,
it rapidly progressed towards burning. Thermal detection didn't work
because it took far too long to get hot.

Slight subject drift...

I had some difficulties with tantalums. I was dealing with a simple
voltage doubler power supply. For some reason, I decided to use
tantalum capacitors instead of the usual electrolytics. The result
was low output and far more ripple at the output than I would have
expected. I eventually found that I had a bag of defective tantalums
with very high ESR (as measured on my Dick Smith ESR meter).
Apparently, I wasn't the only person with the problem. See:
http://ludens.cl/Electron/esr/esr.html
to the right of the photo with the two yellow tantalums. I later
sample tested my small inventory, and but didn't find any more with
high ESR.


--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

On Mon, 19 Nov 2007 08:50:51 +0000, Eeyore
put finger to keyboard and
composed:

Arfa Daily wrote:

they have tiny 85 deg caps fitted that are rated about 2 volts above what they

have to work at

There's nothing wrong with that voltage rating. Why do you think they have a
working voltage rating ?

Graham

I'm aware that solid electros are not relevant to this discussion, but
I found the following datasheet useful because it discusses failure
rates for aluminium electrolytic capacitors:

NSP SERIES – LOW ESR SOLID ALUMINUM ELECTROLYTIC CAPACITOR
http://www.niccomp.com/NSPAppGuide0503.pdf

There is a table at the end which represents a failure rate model as
outlined in MIL-HDBK-217, the Military Handbook for "Reliability
Prediction of Electronic Equipment".

The formula for failure rate (FR) is ...

FR = (BFR) x (temperature factor) x (voltage factor) x (capacitance
value factor)

BFR = Basic Failure Rate for Aluminum Electrolytic Capacitors (per
MIL-HDBK-217F)

FR is influenced by:
- temperature of operation
- applied voltage to voltage rating (voltage ratio factor)
- capacitance value factor

For example, the FR for a 1uF 100V electrolytic capacitor operating at
25C 30V is 1 x BFR.

The same cap operating at its rated voltage would have a 14x greater
failure rate. The voltage factors at voltage ratios of 0.6, 0.7, 0.8
and 0.9 are 2, 3.2, 5.2 and 8.6, respectively. This suggests to me
that any design that allowed for a 50% margin would be 5 times more
reliable than one that operated at rated voltages.

If typical "wet" electros follow the above pattern, then Arfa's
observations would be right on the money.

By comparison, solid electros (as used in current motherboards) appear
to be a *lot* more reliable and according to the datasheet suffer no
degradation in ESR, capacitance or leakage current after being
operated for 7000 hours at rated voltage and temperature (105C).

- Franc Zabkar
--
Please remove one 'i' from my address when replying by email.

For the past 8 years i have been working on this new stuff ... store
returns ... As time goes on i see more & more samsung products inside
several major branded units . I have seen the same laser pickup used
inside those goofy branded players and inside a supposedly expensive
sony and in those 60$ little foldup portables .

Its all made up of who will send the cheapest part that week . Good luck

"Franc Zabkar" wrote in message
...
On Mon, 19 Nov 2007 08:50:51 +0000, Eeyore
put finger to keyboard and
composed:

Arfa Daily wrote:

they have tiny 85 deg caps fitted that are rated about 2 volts above
what they

have to work at

There's nothing wrong with that voltage rating. Why do you think they have
a
working voltage rating ?

Graham

I'm aware that solid electros are not relevant to this discussion, but
I found the following datasheet useful because it discusses failure
rates for aluminium electrolytic capacitors:

NSP SERIES - LOW ESR SOLID ALUMINUM ELECTROLYTIC CAPACITOR
http://www.niccomp.com/NSPAppGuide0503.pdf

There is a table at the end which represents a failure rate model as
outlined in MIL-HDBK-217, the Military Handbook for "Reliability
Prediction of Electronic Equipment".

The formula for failure rate (FR) is ...

FR = (BFR) x (temperature factor) x (voltage factor) x (capacitance
value factor)

BFR = Basic Failure Rate for Aluminum Electrolytic Capacitors (per
MIL-HDBK-217F)

FR is influenced by:
- temperature of operation
- applied voltage to voltage rating (voltage ratio factor)
- capacitance value factor

For example, the FR for a 1uF 100V electrolytic capacitor operating at
25C 30V is 1 x BFR.

The same cap operating at its rated voltage would have a 14x greater
failure rate. The voltage factors at voltage ratios of 0.6, 0.7, 0.8
and 0.9 are 2, 3.2, 5.2 and 8.6, respectively. This suggests to me
that any design that allowed for a 50% margin would be 5 times more
reliable than one that operated at rated voltages.

If typical "wet" electros follow the above pattern, then Arfa's
observations would be right on the money.

By comparison, solid electros (as used in current motherboards) appear
to be a *lot* more reliable and according to the datasheet suffer no
degradation in ESR, capacitance or leakage current after being
operated for 7000 hours at rated voltage and temperature (105C).

- Franc Zabkar
--

That goes along with what Jeff Liebermann said on the subject as well, and
goes a long way towards explaining what I daily observe. It should also
knock on the head, any and all future discussion as to whether electrolytics
should be rated at +30% of applied voltage, for long-term reliability ...
Thanks for your interesting input on the subject, Franc.

Arfa