I know there are some people with good electronics knowledge here, so I
thought I'd ask. I've a Dell PC, maybe 8 years old. I don't want to
throw it out, because it's 64-bit, and I'm a bit short of 64-bit stuff.
But it keeps resetting itself, even with a newly-installed OS. I've
tried reseating everything, which usually works for me, but not this
time. There are about 6 leaking caps on the board. Has anyone here
ever managed to repair a resetting PC by replacing such things?

On 20/11/2014 15:01, Etaoin Shrdlu wrote:
I know there are some people with good electronics knowledge here, so I
thought I'd ask. I've a Dell PC, maybe 8 years old. I don't want to
throw it out, because it's 64-bit, and I'm a bit short of 64-bit stuff.
But it keeps resetting itself, even with a newly-installed OS. I've
tried reseating everything, which usually works for me, but not this
time. There are about 6 leaking caps on the board. Has anyone here
ever managed to repair a resetting PC by replacing such things?

Yes. But it isn't for the faint hearted. I have done it once myself.

Are the capacitors actually leaking vital fluids or just deformed,
bulging and at a rakish angle.

Try running a memory test to see if that is the root cause. The local
memory capacitors seem to suffer the greatest stress on the motherboard.

Getting them out is interesting and inserting new ones into the vacant
positions even more so. If you are experienced at soldering and have a
decent iron and a steady hand then you stand a sporting chance of
success provided you take antistatic precautions. Otherwise you will
finish it off. See the thread about Electronics Advice for details.

Basically you need the right grade of high ripple capacitor at the right
dimensions voltage and capacitance.

Not sure I would bother for an 8yo motherboard though. You can probably
buy something faster than it from the likes of Morgan for ~£100-200.

--
Regards,
Martin Brown

In article , Etaoin
Shrdlu writes
I know there are some people with good electronics knowledge here, so I
thought I'd ask. I've a Dell PC, maybe 8 years old. I don't want to
throw it out, because it's 64-bit, and I'm a bit short of 64-bit stuff.
But it keeps resetting itself, even with a newly-installed OS. I've
tried reseating everything, which usually works for me, but not this
time. There are about 6 leaking caps on the board.

Has anyone here
ever managed to repair a resetting PC by replacing such things?

Yes :-)

Whether you can do it yourself will depend on your skills with a
soldering iron and your desoldering techniques.

Mobos are particularly tricky as the pcb designers break design rules by
not placing thermal reliefs around cap pads (they use plain copper fill)
which requires a lot of heat and good technique to repair.

I have access to good quality temperature controlled soldering irons of
between 45 & 60W which I regard as essential for work of this kind.

I'm not one of those who advocates tacking caps onto pads as I believe
the lead length will result in supply noise and reliability problems.

Quality caps can be had for under a quid each from CPC et al, as
described in the recent 'Electronics Advice' thread.

I wont go into method, there are plenty of guides on youtube.

--
fred
it's a ba-na-na . . . .

Etaoin Shrdlu wrote:
I know there are some people with good electronics knowledge here, so I
thought I'd ask. I've a Dell PC, maybe 8 years old. I don't want to
throw it out, because it's 64-bit, and I'm a bit short of 64-bit stuff.
But it keeps resetting itself, even with a newly-installed OS. I've
tried reseating everything, which usually works for me, but not this
time. There are about 6 leaking caps on the board. Has anyone here
ever managed to repair a resetting PC by replacing such things?

Okay, thanks chaps, I'll try it. I know it's not going to be fun, and
could easily have been persuaded not to bother. I've done loads of
soldering over the years, but yes, it has got much harder as I got
older, more short-sighted, and things got smaller and more packed-in.

I've a pair of head-worn magnifiers, which helps immensely, but makes
you look rather odd. And will use the small pointy bit for the Antex,
of course.

Martin Brown wrote:
On 20/11/2014 15:01, Etaoin Shrdlu wrote:
I know there are some people with good electronics knowledge here, so I
thought I'd ask. I've a Dell PC, maybe 8 years old. I don't want to
throw it out, because it's 64-bit, and I'm a bit short of 64-bit stuff.
But it keeps resetting itself, even with a newly-installed OS. I've
tried reseating everything, which usually works for me, but not this
time. There are about 6 leaking caps on the board. Has anyone here
ever managed to repair a resetting PC by replacing such things?

Yes. But it isn't for the faint hearted. I have done it once myself.

Are the capacitors actually leaking vital fluids or just deformed,
bulging and at a rakish angle.

Bulging at the top, and there is black crusty stuff around what look
like cuts into the top face. There are four affected ones near to the
CPU, and two near to the memory.

Try running a memory test to see if that is the root cause. The local
memory capacitors seem to suffer the greatest stress on the motherboard.

Getting them out is interesting and inserting new ones into the vacant
positions even more so. If you are experienced at soldering and have a
decent iron and a steady hand then you stand a sporting chance of
success provided you take antistatic precautions. Otherwise you will
finish it off. See the thread about Electronics Advice for details.

Basically you need the right grade of high ripple capacitor at the right
dimensions voltage and capacitance.

Not sure I would bother for an 8yo motherboard though. You can probably
buy something faster than it from the likes of Morgan for ~£100-200.

I always try and fix. I'm that mean :-)

fred wrote:
In article , Etaoin
Shrdlu writes
I know there are some people with good electronics knowledge here, so I
thought I'd ask. I've a Dell PC, maybe 8 years old. I don't want to
throw it out, because it's 64-bit, and I'm a bit short of 64-bit stuff.
But it keeps resetting itself, even with a newly-installed OS. I've
tried reseating everything, which usually works for me, but not this
time. There are about 6 leaking caps on the board.

Has anyone here
ever managed to repair a resetting PC by replacing such things?

Yes :-)

Whether you can do it yourself will depend on your skills with a
soldering iron and your desoldering techniques.

Mobos are particularly tricky as the pcb designers break design rules by
not placing thermal reliefs around cap pads (they use plain copper fill)
which requires a lot of heat and good technique to repair.

I have access to good quality temperature controlled soldering irons of
between 45 & 60W which I regard as essential for work of this kind.

I've an old Antex X25, and using it with the pointy bit seems to
transfer much less heat at the end, in addition to it being more accurate.

I'm not one of those who advocates tacking caps onto pads as I believe
the lead length will result in supply noise and reliability problems.

Quality caps can be had for under a quid each from CPC et al, as
described in the recent 'Electronics Advice' thread.

I wont go into method, there are plenty of guides on youtube.

"Etaoin Shrdlu" wrote in message
. uk...
Etaoin Shrdlu wrote:
I know there are some people with good electronics knowledge here, so I
thought I'd ask. I've a Dell PC, maybe 8 years old. I don't want to
throw it out, because it's 64-bit, and I'm a bit short of 64-bit stuff.
But it keeps resetting itself, even with a newly-installed OS. I've
tried reseating everything, which usually works for me, but not this
time. There are about 6 leaking caps on the board. Has anyone here
ever managed to repair a resetting PC by replacing such things?

Okay, thanks chaps, I'll try it. I know it's not going to be fun, and
could easily have been persuaded not to bother. I've done loads of
soldering over the years, but yes, it has got much harder as I got older,
more short-sighted, and things got smaller and more packed-in.

I've a pair of head-worn magnifiers, which helps immensely, but makes you
look rather odd. And will use the small pointy bit for the Antex, of
course.


A good head light would probably help too

Do you mean Sprague?
They make caps.
Well I guess you could try as they at least are not surface mount. Have
you measured voltages or put a scope on the lines to see if its crud that is
doing it?
Resetting tends to usually be ram though.

Brian

--
From the Sofa of Brian Gaff Reply address is active
"Etaoin Shrdlu" wrote in message
...
I know there are some people with good electronics knowledge here, so I
thought I'd ask. I've a Dell PC, maybe 8 years old. I don't want to throw
it out, because it's 64-bit, and I'm a bit short of 64-bit stuff. But it
keeps resetting itself, even with a newly-installed OS. I've tried
reseating everything, which usually works for me, but not this time. There
are about 6 leaking caps on the board. Has anyone here ever managed to
repair a resetting PC by replacing such things?

Phil L wrote:
"Etaoin Shrdlu" wrote in message
. uk...
Etaoin Shrdlu wrote:
I know there are some people with good electronics knowledge here, so I
thought I'd ask. I've a Dell PC, maybe 8 years old. I don't want to
throw it out, because it's 64-bit, and I'm a bit short of 64-bit stuff.
But it keeps resetting itself, even with a newly-installed OS. I've
tried reseating everything, which usually works for me, but not this
time. There are about 6 leaking caps on the board. Has anyone here
ever managed to repair a resetting PC by replacing such things?

Okay, thanks chaps, I'll try it. I know it's not going to be fun, and
could easily have been persuaded not to bother. I've done loads of
soldering over the years, but yes, it has got much harder as I got older,
more short-sighted, and things got smaller and more packed-in.

I've a pair of head-worn magnifiers, which helps immensely, but makes you
look rather odd. And will use the small pointy bit for the Antex, of
course.


A good head light would probably help too


My magnifiers have a light. One of the best things I've bought recently.

Brian Gaff wrote:
Do you mean Sprague?

I was referring to a phenomenon that became known as Capacitor Plague.
http://en.wikipedia.org/wiki/Capacitor_plague

They make caps.
Well I guess you could try as they at least are not surface mount. Have
you measured voltages or put a scope on the lines to see if its crud that is
doing it?

No, I'm just picking on these first as there is obviously something
wrong with them.

Resetting tends to usually be ram though.

I've put known good RAM in from another machine.

Brian

In article , Etaoin
Shrdlu writes
fred wrote:

Whether you can do it yourself will depend on your skills with a
soldering iron and your desoldering techniques.

Mobos are particularly tricky as the pcb designers break design rules by
not placing thermal reliefs around cap pads (they use plain copper fill)
which requires a lot of heat and good technique to repair.

I have access to good quality temperature controlled soldering irons of
between 45 & 60W which I regard as essential for work of this kind.

I've an old Antex X25, and using it with the pointy bit seems to
transfer much less heat at the end, in addition to it being more accurate.

Yep, a pointy tip wont help and 25W is borderline anyway for a filled
power plane (huge heatsink).

In that situation, it may be that lying radial caps flat and tacking
onto existing leads with them as absolutely short as possible may be the
way to go. I absolutely hate it but sometimes you have to work with what
you are given. If you go this way then cut away the body on the top side
and leave the leads behind. The electrolyte is nasty so keep it off your
hands or wear latex gloves.

Feel free to post your intended cap choice for a crit before buying but
the Rubycon range from CPC reference in the Homeplug repair thread look
very good.

--
fred
it's a ba-na-na . . . .

fred wrote:
In article , Etaoin
Shrdlu writes
fred wrote:

Whether you can do it yourself will depend on your skills with a
soldering iron and your desoldering techniques.

Mobos are particularly tricky as the pcb designers break design rules by
not placing thermal reliefs around cap pads (they use plain copper fill)
which requires a lot of heat and good technique to repair.

I have access to good quality temperature controlled soldering irons of
between 45 & 60W which I regard as essential for work of this kind.

I've an old Antex X25, and using it with the pointy bit seems to
transfer much less heat at the end, in addition to it being more
accurate.

Yep, a pointy tip wont help and 25W is borderline anyway for a filled
power plane (huge heatsink).

In that situation, it may be that lying radial caps flat and tacking
onto existing leads with them as absolutely short as possible may be the
way to go. I absolutely hate it but sometimes you have to work with what
you are given. If you go this way then cut away the body on the top side
and leave the leads behind. The electrolyte is nasty so keep it off your
hands or wear latex gloves.

Feel free to post your intended cap choice for a crit before buying but
the Rubycon range from CPC reference in the Homeplug repair thread look
very good.


I already have some with Nichicon on them, but I've no idea if they're
any good. In the past, if I needed something like this, I always bought
a few more. I don't have enough to replace all the ones I'm looking at
here, but I thought I'd try the ones that look the worst first.

On 20/11/2014 15:01, Etaoin Shrdlu wrote:
I know there are some people with good electronics knowledge here, so I
thought I'd ask. I've a Dell PC, maybe 8 years old. I don't want to
throw it out, because it's 64-bit, and I'm a bit short of 64-bit stuff.
But it keeps resetting itself, even with a newly-installed OS. I've
tried reseating everything, which usually works for me, but not this
time. There are about 6 leaking caps on the board. Has anyone here
ever managed to repair a resetting PC by replacing such things?

Yup done a few where they were odd form factors and hence difficult to
replace.

http://wiki.diyfaq.org.uk/index.php?...air#Capacitors

Success rate around 75% - had some where in spite of having dodgy caps,
replacement of those alone did not fix the problems.

--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

John Rumm wrote:
On 20/11/2014 15:01, Etaoin Shrdlu wrote:
I know there are some people with good electronics knowledge here, so I
thought I'd ask. I've a Dell PC, maybe 8 years old. I don't want to
throw it out, because it's 64-bit, and I'm a bit short of 64-bit stuff.
But it keeps resetting itself, even with a newly-installed OS. I've
tried reseating everything, which usually works for me, but not this
time. There are about 6 leaking caps on the board. Has anyone here
ever managed to repair a resetting PC by replacing such things?

Yup done a few where they were odd form factors and hence difficult to
replace.

http://wiki.diyfaq.org.uk/index.php?...air#Capacitors

Success rate around 75% - had some where in spite of having dodgy caps,
replacement of those alone did not fix the problems.


Thanks, that's a good FAQ. I did get a cheap ESR (like £20) meter off
eBay, but haven't had time to work out how to use it. The instructions,
obviously written by someone in the Orient, are beyond me.

fred brought next idea :
In article , Etaoin Shrdlu
writes
I know there are some people with good electronics knowledge here, so I
thought I'd ask. I've a Dell PC, maybe 8 years old. I don't want to
throw it out, because it's 64-bit, and I'm a bit short of 64-bit stuff.
But it keeps resetting itself, even with a newly-installed OS. I've
tried reseating everything, which usually works for me, but not this
time. There are about 6 leaking caps on the board.

Has anyone here
ever managed to repair a resetting PC by replacing such things?

Yes :-)

Whether you can do it yourself will depend on your skills with a soldering
iron and your desoldering techniques.

Mobos are particularly tricky as the pcb designers break design rules by not
placing thermal reliefs around cap pads (they use plain copper fill) which
requires a lot of heat and good technique to repair.

I have access to good quality temperature controlled soldering irons of
between 45 & 60W which I regard as essential for work of this kind.

I'm not one of those who advocates tacking caps onto pads as I believe the
lead length will result in supply noise and reliability problems.

Quality caps can be had for under a quid each from CPC et al, as described in
the recent 'Electronics Advice' thread.

I wont go into method, there are plenty of guides on youtube.

If looks are not important - just burst the caps open, remove the
debris and tack solder to the remnants of the legs.

--
Regards,
Harry (M1BYT) (L)
http://www.ukradioamateur.co.uk

Feel free to post your intended cap choice for a crit before buying but
the Rubycon range from CPC reference in the Homeplug repair thread look
very good.


Talking of caps, I personally go for Panasonic FM and FC series. Can be
got from the likes of Mouser, Digikey and Farnell.

Harry Bloomfield wrote:
fred brought next idea :
In article , Etaoin
Shrdlu writes
I know there are some people with good electronics knowledge here, so I
thought I'd ask. I've a Dell PC, maybe 8 years old. I don't want to
throw it out, because it's 64-bit, and I'm a bit short of 64-bit stuff.
But it keeps resetting itself, even with a newly-installed OS. I've
tried reseating everything, which usually works for me, but not this
time. There are about 6 leaking caps on the board.

Has anyone here
ever managed to repair a resetting PC by replacing such things?

Yes :-)

Whether you can do it yourself will depend on your skills with a
soldering iron and your desoldering techniques.

Mobos are particularly tricky as the pcb designers break design rules
by not placing thermal reliefs around cap pads (they use plain copper
fill) which requires a lot of heat and good technique to repair.

I have access to good quality temperature controlled soldering irons
of between 45 & 60W which I regard as essential for work of this kind.

I'm not one of those who advocates tacking caps onto pads as I believe
the lead length will result in supply noise and reliability problems.

Quality caps can be had for under a quid each from CPC et al, as
described in the recent 'Electronics Advice' thread.

I wont go into method, there are plenty of guides on youtube.

If looks are not important - just burst the caps open, remove the debris
and tack solder to the remnants of the legs.


That's interesting - I'll remember that for an emergency. Anyway, I've
replaced about six of them. It's booted into the OS okay - I'll see how
long it stays up.

fred wrote:
In article , Etaoin
Shrdlu writes
fred wrote:

Whether you can do it yourself will depend on your skills with a
soldering iron and your desoldering techniques.

Mobos are particularly tricky as the pcb designers break design rules by
not placing thermal reliefs around cap pads (they use plain copper fill)
which requires a lot of heat and good technique to repair.

I have access to good quality temperature controlled soldering irons of
between 45 & 60W which I regard as essential for work of this kind.

I've an old Antex X25, and using it with the pointy bit seems to
transfer much less heat at the end, in addition to it being more
accurate.

Yep, a pointy tip wont help and 25W is borderline anyway for a filled
power plane (huge heatsink).

In that situation, it may be that lying radial caps flat and tacking
onto existing leads with them as absolutely short as possible may be the
way to go. I absolutely hate it but sometimes you have to work with what
you are given. If you go this way then cut away the body on the top side
and leave the leads behind. The electrolyte is nasty so keep it off your
hands or wear latex gloves.

Feel free to post your intended cap choice for a crit before buying but
the Rubycon range from CPC reference in the Homeplug repair thread look
very good.


The nackered ones I've taken out are Rubycon.

In article , Stephen
writes


Feel free to post your intended cap choice for a crit before buying but
the Rubycon range from CPC reference in the Homeplug repair thread look
very good.


Talking of caps, I personally go for Panasonic FM and FC series. Can be
got from the likes of Mouser, Digikey and Farnell.

Checking again, my main stock here is Panasonic FM which they
interestingly claim has "40 % to 70 % lower impedance than FC series".
--
fred
it's a ba-na-na . . . .

In article , Etaoin
Shrdlu writes
fred wrote:

Feel free to post your intended cap choice for a crit before buying but
the Rubycon range from CPC reference in the Homeplug repair thread look
very good.


The nackered ones I've taken out are Rubycon.

Hah!, that'll teach me. As mentioned in another reply, on checking
again, my main stock is Panasonic FM series. They appear to be better
spec than either their FC or FK series but at the expense of case size.
Again avail from CPC or RS Online.

The Rubys do still look to have a good spec.
--
fred
it's a ba-na-na . . . .

fred wrote:
In article , Etaoin
Shrdlu writes
fred wrote:

Feel free to post your intended cap choice for a crit before buying but
the Rubycon range from CPC reference in the Homeplug repair thread look
very good.


The nackered ones I've taken out are Rubycon.

Hah!, that'll teach me. As mentioned in another reply, on checking
again, my main stock is Panasonic FM series. They appear to be better
spec than either their FC or FK series but at the expense of case size.
Again avail from CPC or RS Online.

The Rubys do still look to have a good spec.

Well I reckon anything would be better than what was in there before.
Anyway, I changed the six worst-looking ones (one was an 1800uF that I
replaced with a 2200uF, because that was what I had most of), and it's
been running for a few hours now, which is longer than it managed before.

Of course, it might be just down to taking it apart and putting it back
together again.

The pointy bit was good for clearing out the holes (used with a solder
sucker), but useless for actual soldering in this application.

On 20/11/2014 16:55, Etaoin Shrdlu wrote:
John Rumm wrote:
On 20/11/2014 15:01, Etaoin Shrdlu wrote:
I know there are some people with good electronics knowledge here, so I
thought I'd ask. I've a Dell PC, maybe 8 years old. I don't want to
throw it out, because it's 64-bit, and I'm a bit short of 64-bit stuff.
But it keeps resetting itself, even with a newly-installed OS. I've
tried reseating everything, which usually works for me, but not this
time. There are about 6 leaking caps on the board. Has anyone here
ever managed to repair a resetting PC by replacing such things?

Yup done a few where they were odd form factors and hence difficult to
replace.

http://wiki.diyfaq.org.uk/index.php?...air#Capacitors

Success rate around 75% - had some where in spite of having dodgy caps,
replacement of those alone did not fix the problems.


Thanks, that's a good FAQ. I did get a cheap ESR (like £20) meter off
eBay, but haven't had time to work out how to use it. The instructions,
obviously written by someone in the Orient, are beyond me.

Well if you are measuring the cap out of circuit, you simply compare the
reading with the expected value of ESR for the cap. A reading similar to
that expected or lower is generally good. Higher usually indicates that
the cap is failing. Some meters will also report other states such as
open circuit or "leaky".

You can get the expected ESR values from the makers data sheet for the
cap, however I have added a table he

http://wiki.diyfaq.org.uk/index.php?...pair#ESR_Meter

Which has typical values for standard electrolytics. You can use these
as a baseline.



--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

On 20/11/2014 19:17, Etaoin Shrdlu wrote:
fred wrote:
In article , Etaoin
Shrdlu writes
fred wrote:

Whether you can do it yourself will depend on your skills with a
soldering iron and your desoldering techniques.

Mobos are particularly tricky as the pcb designers break design
rules by
not placing thermal reliefs around cap pads (they use plain copper
fill)
which requires a lot of heat and good technique to repair.

I have access to good quality temperature controlled soldering irons of
between 45 & 60W which I regard as essential for work of this kind.

I've an old Antex X25, and using it with the pointy bit seems to
transfer much less heat at the end, in addition to it being more
accurate.

Yep, a pointy tip wont help and 25W is borderline anyway for a filled
power plane (huge heatsink).

In that situation, it may be that lying radial caps flat and tacking
onto existing leads with them as absolutely short as possible may be the
way to go. I absolutely hate it but sometimes you have to work with what
you are given. If you go this way then cut away the body on the top side
and leave the leads behind. The electrolyte is nasty so keep it off your
hands or wear latex gloves.

Feel free to post your intended cap choice for a crit before buying but
the Rubycon range from CPC reference in the Homeplug repair thread look
very good.


The nackered ones I've taken out are Rubycon.

Rubycon are generally thought to be a very good brand (assuming they are
not fakes!) - having said that - any brand can (will) fail in time.

--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

In article , Etaoin
Shrdlu writes

Well I reckon anything would be better than what was in there before.
Anyway, I changed the six worst-looking ones (one was an 1800uF that I
replaced with a 2200uF, because that was what I had most of), and it's
been running for a few hours now, which is longer than it managed before.

You don't hang about :-)

Of course, it might be just down to taking it apart and putting it back
together again.

The pointy bit was good for clearing out the holes (used with a solder
sucker), but useless for actual soldering in this application.

I hope it continues to hold up for you, an extended period of both
memtest86 and prime95 is probably in order and it probably wouldn't do
any harm to run these at a slightly elevated temperature, say in a
cupboard or ventilation limited space to push the envelope a bit.

Using a pointy bit for desoldering is a useful tip, thanks for the
reminder.

--
fred
it's a ba-na-na . . . .

John Rumm wrote:
On 20/11/2014 19:17, Etaoin Shrdlu wrote:
fred wrote:
In article , Etaoin
Shrdlu writes
fred wrote:

Whether you can do it yourself will depend on your skills with a
soldering iron and your desoldering techniques.

Mobos are particularly tricky as the pcb designers break design
rules by
not placing thermal reliefs around cap pads (they use plain copper
fill)
which requires a lot of heat and good technique to repair.

I have access to good quality temperature controlled soldering
irons of
between 45 & 60W which I regard as essential for work of this kind.

I've an old Antex X25, and using it with the pointy bit seems to
transfer much less heat at the end, in addition to it being more
accurate.

Yep, a pointy tip wont help and 25W is borderline anyway for a filled
power plane (huge heatsink).

In that situation, it may be that lying radial caps flat and tacking
onto existing leads with them as absolutely short as possible may be the
way to go. I absolutely hate it but sometimes you have to work with what
you are given. If you go this way then cut away the body on the top side
and leave the leads behind. The electrolyte is nasty so keep it off your
hands or wear latex gloves.

Feel free to post your intended cap choice for a crit before buying but
the Rubycon range from CPC reference in the Homeplug repair thread look
very good.


The nackered ones I've taken out are Rubycon.

Rubycon are generally thought to be a very good brand (assuming they are
not fakes!) - having said that - any brand can (will) fail in time.


It's on a Dell board, and I wouldn't expect them to use any old rubbish.
But yes, like anything, even the best can fail sometimes.

fred wrote:
In article , Etaoin
Shrdlu writes

Well I reckon anything would be better than what was in there before.
Anyway, I changed the six worst-looking ones (one was an 1800uF that I
replaced with a 2200uF, because that was what I had most of), and it's
been running for a few hours now, which is longer than it managed before.

You don't hang about :-)

My sister's taken our little boy out for the evening - I have to make
the most of the opportunity. Been rushing around doing all kind of things.

Of course, it might be just down to taking it apart and putting it back
together again.

The pointy bit was good for clearing out the holes (used with a solder
sucker), but useless for actual soldering in this application.

I hope it continues to hold up for you, an extended period of both
memtest86 and prime95 is probably in order and it probably wouldn't do
any harm to run these at a slightly elevated temperature, say in a
cupboard or ventilation limited space to push the envelope a bit.

Using a pointy bit for desoldering is a useful tip, thanks for the
reminder.

On Thu, 20 Nov 2014 15:01:57 +0000, Etaoin Shrdlu
wrote:

I know there are some people with good electronics knowledge here, so I
thought I'd ask. I've a Dell PC, maybe 8 years old. I don't want to
throw it out, because it's 64-bit, and I'm a bit short of 64-bit stuff.
But it keeps resetting itself, even with a newly-installed OS. I've
tried reseating everything, which usually works for me, but not this
time. There are about 6 leaking caps on the board. Has anyone here
ever managed to repair a resetting PC by replacing such things?

I've fixed many an unstable PC by re-capping the MoBo.

When someone brings in a PC, complaining about its lack of stability
(propensity to randomly reset or lock up), my first action is to take
a swift gander at the CPU VRM caps surrounding the CPU socket to look
for the blatant signs of dried out 'blown' caps (tops domed up and the
anti explosion stress relief 'scribe lines' cracked open with or
without brown staining from leakage of the electrolyte).

I don't think I've ever seen such a lack of capacitor failure
evidence on an unstable PC. If anything, I've seen plenty of such
failing caps on perfectly stable PCs that heve been brought in to have
other issues dealt with. It's surprising just how many caps can fail
in the VRM circuitry before obvious symptoms start kicking in.

It's usually the CPU VRM caps that fail ahead of the other smaller
ones dotted around the board elsewhere since they might well be having
to deal with ripple currents of several tens of amperes (basically
what the CPU core demands from the 1voltish 60 to 80 amp VRM supply
rail).

The other smaller caps only have to contend with the much lower
average duty cycle ripple imposed by the current draw of the load at
the end of a relatively long circuit trace feeding memory slots with
oddball voltages that don't appear directly on any of the extremely
Lo-Z collander ground plane supply rails.

I can only recall just the one occasion when replacing one of these
smaller caps (too small to justify the stress relief 'scribe marks')
near to the dimm slots on an Intel MoBo proved to be an effective cure
to a boot up issue.

Normally, you pick your suspects by MK 1 eyeball on the basis that
they don't have the normal appearance of flatness (or, indeed, a
suggestion of concaveness). In this case, I chose my 'suspect' on the
basis that it merely looked flat as opposed to its neighbours
appearance of just the slightest hint of concaveness (and that was
with the use of a jeweler's loupe!). I think I cured it on that first
'hit', although I may have replaced a few other suspects nearby just
for good measure - I'm not sure since it was a few years ago now.
--
J B Good

On 20/11/2014 19:17, Etaoin Shrdlu wrote:


The nackered ones I've taken out are Rubycon.


It worth checking closely as various korean/chinese sourced capacitors
often have branding very similar to that of the well respected
manufactures.

I have have seen capacitors branded "Rubjcon" and "Rulycon" using the
same font style/colour as Rubycon but with the font size much smaller to
make reading the name somewhat difficult without a magnifying glass.

--
mailto: news {at} admac {dot] myzen {dot} co {dot} uk

In article , Etaoin
Shrdlu scribeth thus
fred wrote:
In article , Etaoin
Shrdlu writes
fred wrote:

Feel free to post your intended cap choice for a crit before buying but
the Rubycon range from CPC reference in the Homeplug repair thread look
very good.


The nackered ones I've taken out are Rubycon.

Hah!, that'll teach me. As mentioned in another reply, on checking
again, my main stock is Panasonic FM series. They appear to be better
spec than either their FC or FK series but at the expense of case size.
Again avail from CPC or RS Online.

The Rubys do still look to have a good spec.

Well I reckon anything would be better than what was in there before.
Anyway, I changed the six worst-looking ones (one was an 1800uF that I
replaced with a 2200uF, because that was what I had most of), and it's
been running for a few hours now, which is longer than it managed before.

Of course, it might be just down to taking it apart and putting it back
together again.

The pointy bit was good for clearing out the holes (used with a solder
sucker), but useless for actual soldering in this application.

I've done a few in the past but its a right PITA doing them;(...
--
Tony Sayer

On Thu, 20 Nov 2014 16:26:45 +0000, Etaoin Shrdlu
wrote:

Brian Gaff wrote:
Do you mean Sprague?

I was referring to a phenomenon that became known as Capacitor Plague.
http://en.wikipedia.org/wiki/Capacitor_plague

They make caps.
Well I guess you could try as they at least are not surface mount. Have
you measured voltages or put a scope on the lines to see if its crud that is
doing it?

No, I'm just picking on these first as there is obviously something
wrong with them.

The chances of success with this strategy are quite high so it's well
worth dealing with the "Obvious Offenders" when your supply of
ammunition is getting low (I've seen plenty of stable MoBos where half
of their VRM caps have 'blown' their tops so there does seem to be a
high level of redundency/margin for failed caps).

Resetting tends to usually be ram though.

That's one possible cause but half the time it's down to bad dimm
slot contacts rather than the ram itself - usually reseating the dimms
effects a fairly permanent cure. Although it's far less common, failed
decoupling caps around the dimm slots can also cause 'bad ram
syndrome'. It's rare because they have a much easier electrical life
and are, generally, a little more remote from the major source of heat
so run cooler to the benefit of extended life.


I've put known good RAM in from another machine.


Which is an obvious 1st line of approach to diagnosis. I'd be
surprised if just replacing the 'obvious suspects' in the VRM area of
the board doesn't provide an immediate cure.

The trick to success is to use a 25 to 35 W antex with a chisel blade
tip (double that for the feebler 'bit inserted _into_ the heating
element lump' type of soldering iron) and don't be afraid to melt a
fair sized blob of multicore tin/lead solder over both capacitor holes
so you can wriggle it out of the board.

A lump of beeswax to re-flux the excess solder will help it adhere
back onto the soldering iron bit after you've sucked the holes dry
using a de-soldering sucking tool[1]. There's never the luxury of
sufficient clearance to waste time crushing the blown cap to gain
better access to the 'stumps' to let you fiddle about with needle nose
pliars to allow each one to be removed one at a time (there certainly
won't be any room to use these stumps to tack solder the replacement
onto without relying upon unfeasibly long component leads).

Once you've discounted all such thoughts in regard to those pragmatic
bodges that can be valid on more sparsely populated boards, you can
concentrate on getting the job done properly without having to worry
about adding excess lead inductance to compromise the original design
rules used in the manufacture of the board nor any worries as to the
security of the solder joints.

[1] The trick of re-inserting the replacement capcitor leads into the
solder filled holes whilst you use a soldering iron to re-flow the
solder is extremely difficult to achieve when you're working 'blind'
as is almost innevitably the case with motherboard recapping work in
the rather congested VRM area. You stand a much better chance of
success if you do take the trouble to clear the old solder out of the
holes so you can wriggle the new cap into place.

Sweating the new cap into the solder filled holes is fine and dandy
when dealing with the other caps standing alone in their own bit of
motherboard real estate where you can readily observe where the wire
ends are going but it's just impractical in the one location on the
board where you can guarantee a replacement of an obviously blown cap
or three is going to effect a cure.
--
J B Good

On Thu, 20 Nov 2014 16:44:37 +0000, John Rumm
wrote:

On 20/11/2014 15:01, Etaoin Shrdlu wrote:
I know there are some people with good electronics knowledge here, so I
thought I'd ask. I've a Dell PC, maybe 8 years old. I don't want to
throw it out, because it's 64-bit, and I'm a bit short of 64-bit stuff.
But it keeps resetting itself, even with a newly-installed OS. I've
tried reseating everything, which usually works for me, but not this
time. There are about 6 leaking caps on the board. Has anyone here
ever managed to repair a resetting PC by replacing such things?

Yup done a few where they were odd form factors and hence difficult to
replace.

http://wiki.diyfaq.org.uk/index.php?...air#Capacitors

Success rate around 75% - had some where in spite of having dodgy caps,
replacement of those alone did not fix the problems.

Yup, it's worth bearing in mind that "**** Happens" and that these
faults can sometimes be due to the fragile high tech silicon going bad
(and even then, it might simply be a bad iinternal lead connection in
the packaging of the chip rather than the chip itself but that's just
a matter of academic interest when you're down to this level of
faultfinding).

I have to say though that I thought I enjoyed a higher success rate
with this sort of repair, perhaps somewhere in the region of 80 to 90
percent (at least in the case of Motherboard VRM re-capping - I
experienced a far lower success rate trying the same repair technique
on ATX PSUs so much so that I've long since given up wasting time on
such repair attempts).
--
J B Good

On 20/11/2014 22:16, John Rumm wrote:
On 20/11/2014 19:17, Etaoin Shrdlu wrote:
fred wrote:
In article , Etaoin
Shrdlu writes
fred wrote:

Whether you can do it yourself will depend on your skills with a
soldering iron and your desoldering techniques.

Mobos are particularly tricky as the pcb designers break design
rules by
not placing thermal reliefs around cap pads (they use plain copper
fill)
which requires a lot of heat and good technique to repair.

I have access to good quality temperature controlled soldering
irons of
between 45 & 60W which I regard as essential for work of this kind.

I've an old Antex X25, and using it with the pointy bit seems to
transfer much less heat at the end, in addition to it being more
accurate.

Yep, a pointy tip wont help and 25W is borderline anyway for a filled
power plane (huge heatsink).

In that situation, it may be that lying radial caps flat and tacking
onto existing leads with them as absolutely short as possible may be the
way to go. I absolutely hate it but sometimes you have to work with what
you are given. If you go this way then cut away the body on the top side
and leave the leads behind. The electrolyte is nasty so keep it off your
hands or wear latex gloves.

Feel free to post your intended cap choice for a crit before buying but
the Rubycon range from CPC reference in the Homeplug repair thread look
very good.


The nackered ones I've taken out are Rubycon.

Rubycon are generally thought to be a very good brand (assuming they are
not fakes!) - having said that - any brand can (will) fail in time.


Be aware that there are counterfeit Rubycons around. some of them are
really poor counterfeits with names such as Rubicon or Rudycon....

You can even get chinese doll capacitors in the field. This is where a
smaller capacitor is put inside the can of a bigger but empty capacitor
and hence passed off aso something of a different spec.

see http://www.flickr.com/photos/47907743@N00/2618014599

Johny B Good wrote:
On Thu, 20 Nov 2014 15:01:57 +0000, Etaoin Shrdlu
wrote:

I know there are some people with good electronics knowledge here, so I
thought I'd ask. I've a Dell PC, maybe 8 years old. I don't want to
throw it out, because it's 64-bit, and I'm a bit short of 64-bit stuff.
But it keeps resetting itself, even with a newly-installed OS. I've
tried reseating everything, which usually works for me, but not this
time. There are about 6 leaking caps on the board. Has anyone here
ever managed to repair a resetting PC by replacing such things?

I've fixed many an unstable PC by re-capping the MoBo.

When someone brings in a PC, complaining about its lack of stability
(propensity to randomly reset or lock up), my first action is to take
a swift gander at the CPU VRM caps surrounding the CPU socket to look
for the blatant signs of dried out 'blown' caps (tops domed up and the
anti explosion stress relief 'scribe lines' cracked open with or
without brown staining from leakage of the electrolyte).

I don't think I've ever seen such a lack of capacitor failure
evidence on an unstable PC. If anything, I've seen plenty of such
failing caps on perfectly stable PCs that heve been brought in to have
other issues dealt with. It's surprising just how many caps can fail
in the VRM circuitry before obvious symptoms start kicking in.

It's usually the CPU VRM caps that fail ahead of the other smaller
ones dotted around the board elsewhere since they might well be having
to deal with ripple currents of several tens of amperes (basically
what the CPU core demands from the 1voltish 60 to 80 amp VRM supply
rail).

The other smaller caps only have to contend with the much lower
average duty cycle ripple imposed by the current draw of the load at
the end of a relatively long circuit trace feeding memory slots with
oddball voltages that don't appear directly on any of the extremely
Lo-Z collander ground plane supply rails.

I can only recall just the one occasion when replacing one of these
smaller caps (too small to justify the stress relief 'scribe marks')
near to the dimm slots on an Intel MoBo proved to be an effective cure
to a boot up issue.

Normally, you pick your suspects by MK 1 eyeball on the basis that
they don't have the normal appearance of flatness (or, indeed, a
suggestion of concaveness). In this case, I chose my 'suspect' on the
basis that it merely looked flat as opposed to its neighbours
appearance of just the slightest hint of concaveness (and that was
with the use of a jeweler's loupe!). I think I cured it on that first
'hit', although I may have replaced a few other suspects nearby just
for good measure - I'm not sure since it was a few years ago now.


Thanks for taking the time to explain this to me, JBG. This is probably
the best and most active NG I subscribe to, and I knew I'd get the
information (and more) that I needed here.

The PC in question has been running happily overnight, so I'm feeling
quite pleased. I replaced some memory caps and some VRM caps, so I'll
probably never know which was the real culprit. But it seems to work
well now, so I'm not going to complain.

On 21/11/2014 09:13, Stephen wrote:
On 20/11/2014 22:16, John Rumm wrote:
On 20/11/2014 19:17, Etaoin Shrdlu wrote:
fred wrote:
In article , Etaoin
Shrdlu writes
fred wrote:

Whether you can do it yourself will depend on your skills with a
soldering iron and your desoldering techniques.

Mobos are particularly tricky as the pcb designers break design
rules by
not placing thermal reliefs around cap pads (they use plain copper
fill)
which requires a lot of heat and good technique to repair.

I have access to good quality temperature controlled soldering
irons of
between 45 & 60W which I regard as essential for work of this kind.

I've an old Antex X25, and using it with the pointy bit seems to
transfer much less heat at the end, in addition to it being more
accurate.

Yep, a pointy tip wont help and 25W is borderline anyway for a filled
power plane (huge heatsink).

In that situation, it may be that lying radial caps flat and tacking
onto existing leads with them as absolutely short as possible may be
the
way to go. I absolutely hate it but sometimes you have to work with
what
you are given. If you go this way then cut away the body on the top
side
and leave the leads behind. The electrolyte is nasty so keep it off
your
hands or wear latex gloves.

Feel free to post your intended cap choice for a crit before buying but
the Rubycon range from CPC reference in the Homeplug repair thread look
very good.


The nackered ones I've taken out are Rubycon.

Rubycon are generally thought to be a very good brand (assuming they are
not fakes!) - having said that - any brand can (will) fail in time.


Be aware that there are counterfeit Rubycons around. some of them are
really poor counterfeits with names such as Rubicon or Rudycon....

You can even get chinese doll capacitors in the field. This is where a
smaller capacitor is put inside the can of a bigger but empty capacitor
and hence passed off aso something of a different spec.

see http://www.flickr.com/photos/47907743@N00/2618014599

Mmm nice ;-)

I had seen that with batteries before, but not capacitors.


--
Cheers,

John.

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