On Jun 13, 1:19*pm, "js.b1" wrote:
Is now a good time to tell you that many recent ECU are conformance
coated or encapsulated so as to prevent "intellectual property theft"?
Therein rendering a car a writeoff with a diagnostic & replacement ECU
bill of 3500+?

CONFORMAL coating has f**k all to do with preventing IP theft. It's
easily stripped to allow rework if you know the solvent to use.

MBQ

On Jun 13, 3:45*pm, "js.b1" wrote:
On Jun 13, 2:31*pm, Bob Minchin

wrote:
Might you be confusing 'conformance coating' with conformal coating? The
latter is a protection against some environmental effects such as
humidity and as a secondary effect makes them a little more difficult to
trace the circuitry and needs local stripping to repair.

The coating, or in some cases potting, was non-removable.
It was found on recent common rail turbo diesel, when challenged the
argument was that it was to protect software intellectual property.

Citation?

MBQ

On 13/06/2010 13:07, tony sayer wrote:
http://www.ecutesting.com/

Unit returned for testing and as they expected found to be faulty with
all the usual faults they have. Kept informed by several texts of the
progress and unit very quickly returned with a bill for £145 plus VAT.
Refitted unit, cured the problem completely and car now back in service
and should be OK for sometime yet.

Seems this is the new way that older cars die off now with "electronic
problems" this one still mechanically fine at 150K miles not bit a bit
of rust anywhere, so good result all around.

No connection apart from being a very satisfied customer etc...

Interesting.

My Audi currently has a problem with the Airbag ECU which leads to the
airbag light being permanently on. We got it diagnosed and it turns out
that it's a fairly well known fault: in cold temperatures the EEPROM in
the unit can randomly flip bits and then it fails a checksum test when
it tries to power on. Theoretically a re-flash would cure it.

The problem is I'd need to dismantle the entire centre console to get at
it and then drive around with the car like that whilst it was being
repaired:

http://forums.audiworld.com/showthread.php?p=15368977

Another common fault are the Infineon power control chips.
Only trouble is I've yet to find a source where I dont have to purchase
several thousand at a time.

If anyone has any pointers to a source of Infineon chips in small
quantities, please say so.

Mark

On Mon, 14 Jun 2010 10:11:46 +0100, tony sayer
wibbled:



But even silicon doesn't survive
forever.


Proof;?...



http://en.wikipedia.org/wiki/Failure...of_electronics

http://soe.stanford.edu/research/pro...ch_dutton.html

It is a reasonable assertion that, above 0K, nothing escapes forever -
though some things my last longer than others.

--
Tim Watts

Managers, politicians and environmentalists: Nature's carbon buffer.

On Mon, 14 Jun 2010 04:04:41 -0700, "Man at B&Q"
wibbled:

On Jun 14, 9:42Â*am, Tim Watts wrote:
On Mon, 14 Jun 2010 00:34:12 +0100, "Dave Liquorice"
wibbled:



On Sun, 13 Jun 2010 18:11:45 +0100, Ron Lowe wrote:

The vast majority of faults are not fancy electronic failures. 90%
are mechanical, connector, chaffed wire, etc. Of the remaining 10%
electronic problems, 90% of those are PSU-related. Only a very small
percentage is actual gubbins-failure.

I like that breakdown, it's about right. I'd add that a lot of the
rare actual gubbins failures can be put down to the PSU throwing a
wobbly or a spike/dip in the supply.

If stuff survives the first few days or weeks of regular use it will
essentially last forever. Always assuming that it has been designed
well, no components right up at the top of their power rating with
inadequate methods of removing the heat resulting in scorched circuit
boards and weakend joints after a year or three of use or simple
component failure due to being under too much stress.

Electrolytic capacitors a a weak point - they tend to be vulnerable to
failure before other components IME.

Not if tye correct parts are specified at the design stage and assuming
you buy from a reputable supplier so that you actually get those parts.
The latter is one of the major differences between cheap as chips stuff
and expensive automotive grade stuff.

That affects the longevity sure, but even the best electrolytic will not
last "forever". They are wet devices and given long enough, they will dry
out. Even a "perfectly" sealed device will be subject to H2O migration
through the can.

But even silicon doesn't survive forever.

Essentially, again if specc'ed correctly and sourced from a manufacturer
who know what they are doing.

It's the difference between something that survives for 5 years, 20 years
and 50 years. No-one is going to manufacture ECUs from space-certified
super robust chips, so that brings us back into the realm of a couple of
decades or 3 decades if you're really lucky, especially with the trend
towards few-atom thick gates in FETs.

All this overlooks the fact that most manufacturers don't care if their
kit drops dead after 10 years, or 20 years for the high end consumer
grade manufacturers. Plenty of tat merchants are happy if it survives the
statutory guarantee period!






--
Tim Watts

Managers, politicians and environmentalists: Nature's carbon buffer.

On Mon, 14 Jun 2010 12:48:48 +0100, "Mark"
wibbled:

Another common fault are the Infineon power control chips. Only trouble
is I've yet to find a source where I dont have to purchase several
thousand at a time.

If anyone has any pointers to a source of Infineon chips in small
quantities, please say so.

Mark

digikey?



--
Tim Watts

Managers, politicians and environmentalists: Nature's carbon buffer.

In article , Tim Watts
scribeth thus
On Mon, 14 Jun 2010 10:11:46 +0100, tony sayer
wibbled:



But even silicon doesn't survive
forever.


Proof;?...



http://en.wikipedia.org/wiki/Failure...of_electronics

http://soe.stanford.edu/research/pro...ch_dutton.html

It is a reasonable assertion that, above 0K, nothing escapes forever -
though some things my last longer than others.


Yes that sure sez that they can fail, but that old Grundig portable
we've got built sometime on 1958 is still going .. nice tone too, 'tho
thats prolly Germanium trannies in that!..

The old QUAD 33/303 my missus uses for her audio is 1967 vintage
original semis, caps changed and still to spec)..
--
Tony Sayer

In message , "Dave Plowman (News)"
writes
In article ,
tony sayer wrote:
But further articles indicate that there is a growing market for
electronic assembly replacements on cars which I suppose is simply
market driven by the demand and the silly prices for new manufacturer
replacements and the growing use of electronic assemblies. It seems for
instance that the firm I referred to spend as much time repairing
electronic dashboards as much else!...

Snag comes in with multi layer PCBs. Makes many repairs near impossible.

I once had a Motorola portable radio with a burn up on a 3 layer PCB.
We were so desperate for the set that I drilled out a 10mm hole through
the damage and with the aid of the exceedingly good track layout in the
manual linked every track across the hole. It worked!! Trouble was it
got nicked on the next job it went out on :-(


--
Bill

In article ,
Bill wrote:
Snag comes in with multi layer PCBs. Makes many repairs near impossible.

I once had a Motorola portable radio with a burn up on a 3 layer PCB.
We were so desperate for the set that I drilled out a 10mm hole through
the damage and with the aid of the exceedingly good track layout in the
manual linked every track across the hole. It worked!! Trouble was it
got nicked on the next job it went out on :-(

That's the problem. Unless you have details of the PCB design, working it
out isn't cost effective for a one off.

--
* What do they call a coffee break at the Lipton Tea Company? *

Dave Plowman London SW
To e-mail, change noise into sound.

In article , Dave Plowman (News)
scribeth thus
In article ,
Bill wrote:
Snag comes in with multi layer PCBs. Makes many repairs near impossible.

I once had a Motorola portable radio with a burn up on a 3 layer PCB.
We were so desperate for the set that I drilled out a 10mm hole through
the damage and with the aid of the exceedingly good track layout in the
manual linked every track across the hole. It worked!! Trouble was it
got nicked on the next job it went out on :-(

That's the problem. Unless you have details of the PCB design, working it
out isn't cost effective for a one off.


Yeabut just how many times does that happen compared to the more usual
run of the mill faults?. Don't think I've ever had to do anything to a
multilayer PCB...
--
Tony Sayer

"August West" wrote in message
...


And when did you last buy a device that came with a schematic,
nevermind a full board layout?

There is a full circuit diagram attached to the cover on my boiler, its is
29 years old though.

My PC came with a PCB layout but no circuit diagram.

In message , Dave Osborne
writes
geoff wrote:
In message o.uk,
Dave Liquorice writes

If stuff survives the first few days or weeks of regular use it will
essentially last forever. Always assuming that it has been designed
well, no components right up at the top of their power rating with
inadequate methods of removing the heat resulting in scorched circuit
boards and weakend joints after a year or three of use or simple
component failure due to being under too much stress.

Lovely sweeping statements based on invalid assumptions there


Not at all.

http://en.wikipedia.org/wiki/Bathtub_curve

Yes, at all

Your assumptions concerning good design, components not being stressed
and heat transit are only ones that can be made in an ideal world

they are certainly not encountered in real consumer electronics

And I'm not sure how you equate "essentially last forever" with what
parts 2 and 3 of the curve - random and wear out failures

--
geoff

In message , Tim Lamb
writes
In message , geoff
writes
In message o.uk,
Dave Liquorice writes
On Sun, 13 Jun 2010 18:11:45 +0100, Ron Lowe wrote:

The vast majority of faults are not fancy electronic failures. 90% are
mechanical, connector, chaffed wire, etc. Of the remaining 10%
electronic problems, 90% of those are PSU-related. Only a very small
percentage is actual gubbins-failure.

I like that breakdown, it's about right. I'd add that a lot of the
rare actual gubbins failures can be put down to the PSU throwing a
wobbly or a spike/dip in the supply.

If stuff survives the first few days or weeks of regular use it will
essentially last forever. Always assuming that it has been designed
well, no components right up at the top of their power rating with
inadequate methods of removing the heat resulting in scorched circuit
boards and weakend joints after a year or three of use or simple
component failure due to being under too much stress.

Lovely sweeping statements based on invalid assumptions there

I'm very glad to find there are so many ECU experts present as I just
happen to have a *dead* '97 Golf Gti obstructing one of my barns.


That would make a good hen house, that would

--
geoff

In message
, Man
at B&Q writes
On Jun 14, 1:17*am, geoff wrote:
In message o.uk, Dave
Liquorice writes

On Sun, 13 Jun 2010 18:11:45 +0100, Ron Lowe wrote:

The vast majority of faults are not fancy electronic failures. 90% are
mechanical, connector, chaffed wire, etc. Of the remaining 10%
electronic problems, 90% of those are PSU-related. Only a very small
percentage is actual gubbins-failure.

I like that breakdown, it's about right. I'd add that a lot of the
rare actual gubbins failures can be put down to the PSU throwing a
wobbly or a spike/dip in the supply.

If stuff survives the first few days or weeks of regular use it will
essentially last forever. Always assuming that it has been designed
well, no components right up at the top of their power rating with
inadequate methods of removing the heat resulting in scorched circuit
boards and weakend joints after a year or three of use or simple
component failure due to being under too much stress.

Lovely sweeping statements based on invalid assumptions there

Pretty accurate actually.

When you've repaired as many pcbs as I have, come back and tell me

--
geoff

In message o.uk, Dave
Liquorice writes
On 14 Jun 2010 08:32:51 GMT, Huge wrote:

If stuff survives the first few days or weeks of regular use it
will
essentially last forever.

Err, no. Not for nothing is it called "bathtub curve".

I said "essentially". The bottom of the bathtub in my experiance is
longer than the useful life of the kit. ie the kit is well
superceeded before it fails.

So what, exactly, is your extensive experience?

--
geoff

In message , Tim Watts
writes
On Mon, 14 Jun 2010 00:34:12 +0100, "Dave Liquorice"
wibbled:

On Sun, 13 Jun 2010 18:11:45 +0100, Ron Lowe wrote:

The vast majority of faults are not fancy electronic failures. 90% are
mechanical, connector, chaffed wire, etc. Of the remaining 10%
electronic problems, 90% of those are PSU-related. Only a very small
percentage is actual gubbins-failure.

I like that breakdown, it's about right. I'd add that a lot of the rare
actual gubbins failures can be put down to the PSU throwing a wobbly or
a spike/dip in the supply.

If stuff survives the first few days or weeks of regular use it will
essentially last forever. Always assuming that it has been designed
well, no components right up at the top of their power rating with
inadequate methods of removing the heat resulting in scorched circuit
boards and weakend joints after a year or three of use or simple
component failure due to being under too much stress.

Electrolytic capacitors a a weak point - they tend to be vulnerable to
failure before other components IME. But even silicon doesn't survive
forever.

Better tell Katie Price


--
geoff

In message
, Man
at B&Q writes
On Jun 14, 9:42*am, Tim Watts wrote:
On Mon, 14 Jun 2010 00:34:12 +0100, "Dave Liquorice"
wibbled:



On Sun, 13 Jun 2010 18:11:45 +0100, Ron Lowe wrote:

The vast majority of faults are not fancy electronic failures. 90% are
mechanical, connector, chaffed wire, etc. Of the remaining 10%
electronic problems, 90% of those are PSU-related. Only a very small
percentage is actual gubbins-failure.

I like that breakdown, it's about right. I'd add that a lot of the rare
actual gubbins failures can be put down to the PSU throwing a wobbly or
a spike/dip in the supply.

If stuff survives the first few days or weeks of regular use it will
essentially last forever. Always assuming that it has been designed
well, no components right up at the top of their power rating with
inadequate methods of removing the heat resulting in scorched circuit
boards and weakend joints after a year or three of use or simple
component failure due to being under too much stress.

Electrolytic capacitors a a weak point - they tend to be vulnerable to
failure before other components IME.

Not if tye correct parts are specified at the design stage and
assuming you buy from a reputable supplier so that you actually get
those parts. The latter is one of the major differences between cheap
as chips stuff and expensive automotive grade stuff.

But even silicon doesn't survive forever.

Essentially, again if specc'ed correctly and sourced from a
manufacturer who know what they are doing.

Here we go - back to unrealistic assumptions

--
geoff

In message , Jim
writes
On 13/06/2010 13:07, tony sayer wrote:
http://www.ecutesting.com/

Unit returned for testing and as they expected found to be faulty with
all the usual faults they have. Kept informed by several texts of the
progress and unit very quickly returned with a bill for £145 plus VAT.
Refitted unit, cured the problem completely and car now back in service
and should be OK for sometime yet.

Seems this is the new way that older cars die off now with "electronic
problems" this one still mechanically fine at 150K miles not bit a bit
of rust anywhere, so good result all around.

No connection apart from being a very satisfied customer etc...

Interesting.

My Audi currently has a problem with the Airbag ECU which leads to the
airbag light being permanently on. We got it diagnosed and it turns out
that it's a fairly well known fault: in cold temperatures the EEPROM in
the unit can randomly flip bits and then it fails a checksum test when
it tries to power on. Theoretically a re-flash would cure it.

Can't be, its electronics, it lasts forever

--
geoff

On Mon, 14 Jun 2010 19:53:30 +0100, geoff wrote:

I said "essentially". The bottom of the bathtub in my experiance
is
longer than the useful life of the kit. ie the kit is well
superceeded before it fails.

So what, exactly, is your extensive experience?

Another who reads what they want to read not what is written. Who
said anything about "extensive"?

--
Cheers
Dave.

In article ,
geoff wrote:
In message o.uk, Dave
Liquorice writes
On 14 Jun 2010 08:32:51 GMT, Huge wrote:

If stuff survives the first few days or weeks of regular use it
will
essentially last forever.

Err, no. Not for nothing is it called "bathtub curve".

I said "essentially". The bottom of the bathtub in my experiance is
longer than the useful life of the kit. ie the kit is well
superceeded before it fails.

So what, exactly, is your extensive experience?

I'd guess Dave is talking about pro broadcast gear and in that respect I'd
agree with him. It's generally not engineered by bean counters. ;-)

--
*Horn broken. - Watch for finger.

Dave Plowman London SW
To e-mail, change noise into sound.

In article ,
tony sayer wrote:
That's the problem. Unless you have details of the PCB design, working
it out isn't cost effective for a one off.


Yeabut just how many times does that happen compared to the more usual
run of the mill faults?. Don't think I've ever had to do anything to a
multilayer PCB...

I mention it because it has happened to me. On an aftermarket ECU I know
quite well. Offered to have a go at repairing one which had had a fairly
major fault at the ignition output and had burned some tracks on the board
- including an (some) inner one(s). Circuit diagram etc readily available.
But not the PC board design. It proved cheaper to rebuild it with a new
PCB, junking all low cost components.

--
*The colder the X-ray table, the more of your body is required on it *

Dave Plowman London SW
To e-mail, change noise into sound.

In message , "Dave Plowman (News)"
writes
In article ,
geoff wrote:
In message o.uk, Dave
Liquorice writes
On 14 Jun 2010 08:32:51 GMT, Huge wrote:

If stuff survives the first few days or weeks of regular use it
will
essentially last forever.

Err, no. Not for nothing is it called "bathtub curve".

I said "essentially". The bottom of the bathtub in my experiance is
longer than the useful life of the kit. ie the kit is well
superceeded before it fails.

So what, exactly, is your extensive experience?

I'd guess Dave is talking about pro broadcast gear and in that respect I'd
agree with him. It's generally not engineered by bean counters. ;-)

Somewhat left field of real world then

--
geoff

On Mon, 14 Jun 2010 14:19:32 +0100, tony sayer
wibbled:

Yes that sure sez that they can fail, but that old Grundig portable
we've got built sometime on 1958 is still going .. nice tone too, 'tho
thats prolly Germanium trannies in that!..

The old QUAD 33/303 my missus uses for her audio is 1967 vintage
original semis, caps changed and still to spec)..

And germanium wasn't immune either. My old dad had a germanium
"receiver" (tuner + amp) and it was forever, after about 10 years of
service) frying the power output bipolars (I guess heat related doping
migration - failure was usually gradual). They were a bugger to get too -
but just about possible. The circuit diagram did have DC test voltages at
various points which made fault finding fairly simple with nothing more
than a multimeter. It got serviced 2 or 3 times by us and was still
working (sort of) when about 35 years old. Only a 25W stereo amp too -
into 15W speakers and turning it up to half max would blow your eardrums
off. The 1/10 button remained depressed for most of the time.



--
Tim Watts

Managers, politicians and environmentalists: Nature's carbon buffer.

wrote:
On 14 Jun,
"Man at B&Q" wrote:

Electrolytic capacitors a a weak point - they tend to be vulnerable to
failure before other components IME.
Not if tye correct parts are specified at the design stage and
assuming you buy from a reputable supplier so that you actually get
those parts. The latter is one of the major differences between cheap
as chips stuff and expensive automotive grade stuff.

But even silicon doesn't survive forever.
Essentially, again if specc'ed correctly and sourced from a
manufacturer who know what they are doing.

Depends on the spec. Generally under-running helps longevity, but not always
with electrolytics. Some (most) specifications are for a limited life.


The failure modes in semiconductors are - apart from gross overload -
either temperature cycling that fatigues joints ( simple failure) or
cracks seals leading to poisoning of the silicon, or high temperature
operation that leads to doping migration, and eventual out of spec drift
- which can lead to either failure to operate at ends of temp range, or
gross failure if the component is stressed.

Mil spec semiconductors have better seals and pay attention to
differential thermal coefficients in the packages.

However its rare to see medium term failures like these: either it goes
quickly, because its really over stressed, or it lasts many many years.

Some forms of flash and EPROM may fail sooner due to other issues: they
depend on charge retention.

That can leak away, leading to bit corruption.

Other effects that can lead to failure that looks like time related
failure of the chips, can be traced to time related failures in other
components, leading to increased stress on the chips. E.g. drying
electrolytics that lead to instability and/or increased current flow in
semiconductors.

Or simple one time overloads, due to voltage spikes etc. These can
damage without destroying, but lead to shortened life.

On Tue, 15 Jun 2010 00:01:20 +0100, wrote:

On 14 Jun,
tony sayer wrote:


Yes that sure sez that they can fail, but that old Grundig portable
we've got built sometime on 1958 is still going .. nice tone too, 'tho
thats prolly Germanium trannies in that!..

I've still got a radio upstairs dating from the early 30s. It's a year or two
since I last used it but it was still working ok, despite having the original
electrolytics in the smoothing. Some others have been changed, and
modifications were done in the late 60s. I now wish I hadn't tried to improve
its performance then.

Is that the KW2000a?

:-)

--
Frank Erskine

Seems this is the new way that older cars die off now with "electronic
problems" this one still mechanically fine at 150K miles not bit a bit
of rust anywhere, so good result all around.

I had a similar issue with the ABS on a 1995 850 T5 a few years back. I
bought the security screwdriver to get into the ECU (about £3), took it
apart, re-soldered everything and re-fitted. ABS cured, no further issues.

I think over time that the joints to the PCB-mounted solenoids that operate
the hydraulic valves may crack and re-soldering sorts them out.

On Jun 14, 7:52*pm, geoff wrote:
In message
, Man
at B&Q writes

On Jun 14, 1:17*am, geoff wrote:
In message o.uk, Dave
Liquorice writes

On Sun, 13 Jun 2010 18:11:45 +0100, Ron Lowe wrote:

The vast majority of faults are not fancy electronic failures. 90% are
mechanical, connector, chaffed wire, etc. Of the remaining 10%
electronic problems, 90% of those are PSU-related. Only a very small
percentage is actual gubbins-failure.

I like that breakdown, it's about right. I'd add that a lot of the
rare actual gubbins failures can be put down to the PSU throwing a
wobbly or a spike/dip in the supply.

If stuff survives the first few days or weeks of regular use it will
essentially last forever. Always assuming that it has been designed
well, no components right up at the top of their power rating with
inadequate methods of removing the heat resulting in scorched circuit
boards and weakend joints after a year or three of use or simple
component failure due to being under too much stress.

Lovely sweeping statements based on invalid assumptions there

Pretty accurate actually.

When you've repaired as many pcbs as I have, come back and tell me

Not until you have designed as much electronics as I have.

MBQ

On Jun 14, 7:49*pm, geoff wrote:
In message , Dave Osborne
writes



geoff wrote:
In message o.uk,
Dave *Liquorice writes

If stuff survives the first few days or weeks of regular use it will
essentially last forever. Always assuming that it has been designed
well, no components right up at the top of their power rating with
inadequate methods of removing the heat resulting in scorched circuit
boards and weakend joints after a year or three of use or simple
component failure due to being under too much stress.

Lovely sweeping statements based on invalid assumptions there

Not at all.

http://en.wikipedia.org/wiki/Bathtub_curve

Yes, at all

Your assumptions concerning good design, components not being stressed
and heat transit are only ones that can be made in an ideal world

they are certainly not encountered in real consumer electronics


We were talking car ECUs.

MBQ

On Jun 14, 8:00*pm, geoff wrote:
In message
, Man
at B&Q writes

On Jun 14, 9:42*am, Tim Watts wrote:
On Mon, 14 Jun 2010 00:34:12 +0100, "Dave Liquorice"
wibbled:

On Sun, 13 Jun 2010 18:11:45 +0100, Ron Lowe wrote:

The vast majority of faults are not fancy electronic failures. 90% are
mechanical, connector, chaffed wire, etc. Of the remaining 10%
electronic problems, 90% of those are PSU-related. Only a very small
percentage is actual gubbins-failure.

I like that breakdown, it's about right. I'd add that a lot of the rare
actual gubbins failures can be put down to the PSU throwing a wobbly or
a spike/dip in the supply.

If stuff survives the first few days or weeks of regular use it will
essentially last forever. Always assuming that it has been designed
well, no components right up at the top of their power rating with
inadequate methods of removing the heat resulting in scorched circuit
boards and weakend joints after a year or three of use or simple
component failure due to being under too much stress.

Electrolytic capacitors a a weak point - they tend to be vulnerable to
failure before other components IME.

Not if tye correct parts are specified at the design stage and
assuming you buy from a reputable supplier so that you actually get
those parts. The latter is one of the major differences between cheap
as chips stuff and expensive automotive grade stuff.

But even silicon doesn't survive forever.

Essentially, again if specc'ed correctly and sourced from a
manufacturer who know what they are doing.

Here we go - back to unrealistic assumptions

In the world of dodgy boiler PCBs, maybe.

MBQ

The Natural Philosopher wrote:

Mil spec semiconductors have better seals and pay attention to
differential thermal coefficients in the packages.


Bumped into a chip once (NEC V40 IIRC) where the extended range one was
done on a bigger technology - 8 micron, not 5, or something like that.
Can't check, the book is at work.

Andy

On Jun 15, 7:27*pm, Andy Champ wrote:
The Natural Philosopher wrote:

Mil spec semiconductors have better seals and pay attention to
differential thermal coefficients in the packages.

Bumped into a chip once (NEC V40 IIRC) where the extended range one was
done on a bigger technology - 8 micron, not 5, or something like that.
Can't check, the book is at work.


If it was mil spec that may have had more to do with a mil qualified
production line not being available for the smaller geometry, or it
may be realated to radiation hardening.

MBQ

In message
, Man
at B&Q writes
On Jun 14, 7:49*pm, geoff wrote:
In message , Dave Osborne
writes



geoff wrote:
In message o.uk,
Dave *Liquorice writes

If stuff survives the first few days or weeks of regular use it will
essentially last forever. Always assuming that it has been designed
well, no components right up at the top of their power rating with
inadequate methods of removing the heat resulting in scorched circuit
boards and weakend joints after a year or three of use or simple
component failure due to being under too much stress.

Lovely sweeping statements based on invalid assumptions there

Not at all.

http://en.wikipedia.org/wiki/Bathtub_curve

Yes, at all

Your assumptions concerning good design, components not being stressed
and heat transit are only ones that can be made in an ideal world

they are certainly not encountered in real consumer electronics


We were talking car ECUs.

Were we ****

"Let me show you what it followed on from

"hit it with the heel of
your 'and'"

Absolutely. First rule of electronic repair, hit it.
if that doesn't work, hit it again, harder.

When you are as experienced as me you will do this without prompting


Absolutely.

In our electronics lab where we maintain *very* expensive electronic and
electro/hydraulic equipment, whacking things with a rubber hammer is a
standard fault-finding technique.

The vast majority of faults are not fancy electronic failures.
90% are mechanical, connector, chaffed wire, etc.
Of the remaining 10% electronic problems, 90% of those are PSU-related.
Only a very small percentage is actual gubbins-failure."

Nice attempt at a swerve there
--
geoff

In message
, Man
at B&Q writes
On Jun 14, 7:52*pm, geoff wrote:
In message
, Man
at B&Q writes

On Jun 14, 1:17*am, geoff wrote:
In message o.uk, Dave
Liquorice writes

On Sun, 13 Jun 2010 18:11:45 +0100, Ron Lowe wrote:

The vast majority of faults are not fancy electronic failures. 90% are
mechanical, connector, chaffed wire, etc. Of the remaining 10%
electronic problems, 90% of those are PSU-related. Only a very small
percentage is actual gubbins-failure.

I like that breakdown, it's about right. I'd add that a lot of the
rare actual gubbins failures can be put down to the PSU throwing a
wobbly or a spike/dip in the supply.

If stuff survives the first few days or weeks of regular use it will
essentially last forever. Always assuming that it has been designed
well, no components right up at the top of their power rating with
inadequate methods of removing the heat resulting in scorched circuit
boards and weakend joints after a year or three of use or simple
component failure due to being under too much stress.

Lovely sweeping statements based on invalid assumptions there

Pretty accurate actually.

When you've repaired as many pcbs as I have, come back and tell me

Not until you have designed as much electronics as I have.

I've designed plenty from spacework to military in my time

But keep up trying to deflect ...



--
geoff

In message
, Man
at B&Q writes
On Jun 14, 8:00*pm, geoff wrote:
In message
, Man
at B&Q writes

On Jun 14, 9:42*am, Tim Watts wrote:
On Mon, 14 Jun 2010 00:34:12 +0100, "Dave Liquorice"
wibbled:

On Sun, 13 Jun 2010 18:11:45 +0100, Ron Lowe wrote:

The vast majority of faults are not fancy electronic failures. 90% are
mechanical, connector, chaffed wire, etc. Of the remaining 10%
electronic problems, 90% of those are PSU-related. Only a very small
percentage is actual gubbins-failure.

I like that breakdown, it's about right. I'd add that a lot of the rare
actual gubbins failures can be put down to the PSU throwing a wobbly or
a spike/dip in the supply.

If stuff survives the first few days or weeks of regular use it will
essentially last forever. Always assuming that it has been designed
well, no components right up at the top of their power rating with
inadequate methods of removing the heat resulting in scorched circuit
boards and weakend joints after a year or three of use or simple
component failure due to being under too much stress.

Electrolytic capacitors a a weak point - they tend to be vulnerable to
failure before other components IME.

Not if tye correct parts are specified at the design stage and
assuming you buy from a reputable supplier so that you actually get
those parts. The latter is one of the major differences between cheap
as chips stuff and expensive automotive grade stuff.

But even silicon doesn't survive forever.

Essentially, again if specc'ed correctly and sourced from a
manufacturer who know what they are doing.

Here we go - back to unrealistic assumptions

In the world of dodgy boiler PCBs, maybe.

Yes

--
geoff

In message , geoff
writes
In message
, Man
at B&Q writes
On Jun 14, 8:00*pm, geoff wrote:
In message
, Man
at B&Q writes

On Jun 14, 9:42*am, Tim Watts wrote:
On Mon, 14 Jun 2010 00:34:12 +0100, "Dave Liquorice"
wibbled:

On Sun, 13 Jun 2010 18:11:45 +0100, Ron Lowe wrote:

The vast majority of faults are not fancy electronic failures. 90% are
mechanical, connector, chaffed wire, etc. Of the remaining 10%
electronic problems, 90% of those are PSU-related. Only a very small
percentage is actual gubbins-failure.

I like that breakdown, it's about right. I'd add that a lot of the rare
actual gubbins failures can be put down to the PSU throwing a wobbly or
a spike/dip in the supply.

If stuff survives the first few days or weeks of regular use it will
essentially last forever. Always assuming that it has been designed
well, no components right up at the top of their power rating with
inadequate methods of removing the heat resulting in scorched circuit
boards and weakend joints after a year or three of use or simple
component failure due to being under too much stress.

Electrolytic capacitors a a weak point - they tend to be vulnerable to
failure before other components IME.

Not if tye correct parts are specified at the design stage and
assuming you buy from a reputable supplier so that you actually get
those parts. The latter is one of the major differences between cheap
as chips stuff and expensive automotive grade stuff.

But even silicon doesn't survive forever.

Essentially, again if specc'ed correctly and sourced from a
manufacturer who know what they are doing.

Here we go - back to unrealistic assumptions

In the world of dodgy boiler PCBs, maybe.

Yes

Its an ideal example of what happens when all these conditions that, who
was it, dave ? stipulated, just don't exist

It also ignores the fact that plenty of electronics is designed to fail,
just like other parts in various commercial goods where there is money
to be made from spare parts

--
geoff

"tony sayer" wrote in message
...

Might be of interest to those who do their own car DIY.

We run, as a second car, an elderly Volvo 850 estate and apart from
being quite old (1996) she still runs fine and is quite adequate for
what we need.

However the MOT test the other day threw up that the ABS light wasn't
behaving quite as it ought and the TRACS system wasn't quite what it
should be either, and a diagnostic test showed the ABS controller was
reporting that the hydraulic pump was U/S apart from other misc faults.

Much shaking of heads at the small local garage and lots of whistling
thru the teeth that its going to cost yer a small fortune as a new one
at the Volvo dealer will be a lot more then what the cars ever worth, so
off to the scrap heap for the 850 :-(.

Thats until a web search threw up,

http://www.ecutesting.com/

Unit returned for testing and as they expected found to be faulty with
all the usual faults they have. Kept informed by several texts of the
progress and unit very quickly returned with a bill for £145 plus VAT.
Refitted unit, cured the problem completely and car now back in service
and should be OK for sometime yet.

Seems this is the new way that older cars die off now with "electronic
problems" this one still mechanically fine at 150K miles not bit a bit
of rust anywhere, so good result all around.

No connection apart from being a very satisfied customer etc...
--
Tony Sayer


Join the UK Volvo Forum and ask questions there.

http://www.volvoforums.org.uk/forumdisplay.php?f=16

I don't have an 850. I have two 240's.
I have been a member for many years.
The Volvo UK Forum is excellent.

In article ,
AlanD wrote:


Seems this is the new way that older cars die off now with "electronic
problems" this one still mechanically fine at 150K miles not bit a bit
of rust anywhere, so good result all around.

I had a similar issue with the ABS on a 1995 850 T5 a few years back. I
bought the security screwdriver to get into the ECU (about £3), took it
apart, re-soldered everything and re-fitted. ABS cured, no further
issues.

I think over time that the joints to the PCB-mounted solenoids that
operate the hydraulic valves may crack and re-soldering sorts them out.

Anything that 'vibrates' or transmits some movement in any way which is
soldered direct to the PCB is a likely failure area with time. Hence
things like large transformers not usually being directly mounted. Where
they are - like TV LOPT - is a common place for failed solder joints.

--
*I brake for no apparent reason.

Dave Plowman London SW
To e-mail, change noise into sound.

In article 6mURn.45658$g76.18280@hurricane, clonet
scribeth thus


"tony sayer" wrote in message
...

Might be of interest to those who do their own car DIY.

We run, as a second car, an elderly Volvo 850 estate and apart from
being quite old (1996) she still runs fine and is quite adequate for
what we need.

However the MOT test the other day threw up that the ABS light wasn't
behaving quite as it ought and the TRACS system wasn't quite what it
should be either, and a diagnostic test showed the ABS controller was
reporting that the hydraulic pump was U/S apart from other misc faults.

Much shaking of heads at the small local garage and lots of whistling
thru the teeth that its going to cost yer a small fortune as a new one
at the Volvo dealer will be a lot more then what the cars ever worth, so
off to the scrap heap for the 850 :-(.

Thats until a web search threw up,

http://www.ecutesting.com/

Unit returned for testing and as they expected found to be faulty with
all the usual faults they have. Kept informed by several texts of the
progress and unit very quickly returned with a bill for £145 plus VAT.
Refitted unit, cured the problem completely and car now back in service
and should be OK for sometime yet.

Seems this is the new way that older cars die off now with "electronic
problems" this one still mechanically fine at 150K miles not bit a bit
of rust anywhere, so good result all around.

No connection apart from being a very satisfied customer etc...
--
Tony Sayer


Join the UK Volvo Forum and ask questions there.

http://www.volvoforums.org.uk/forumdisplay.php?f=16

I don't have an 850. I have two 240's.
I have been a member for many years.
The Volvo UK Forum is excellent.



Yes seen that, but its only since the unit foxed the local mech's that
it became an issue. Never needed any other questions or things doing..
--
Tony Sayer

On Jun 15, 8:53*pm, geoff wrote:
In message
, Man
at B&Q writes

On Jun 14, 7:49*pm, geoff wrote:
In message , Dave Osborne
writes

geoff wrote:
In message o.uk,
Dave *Liquorice writes

If stuff survives the first few days or weeks of regular use it will
essentially last forever. Always assuming that it has been designed
well, no components right up at the top of their power rating with
inadequate methods of removing the heat resulting in scorched circuit
boards and weakend joints after a year or three of use or simple
component failure due to being under too much stress.

Lovely sweeping statements based on invalid assumptions there

Not at all.

http://en.wikipedia.org/wiki/Bathtub_curve

Yes, at all

Your assumptions concerning good design, components not being stressed
and heat transit are only ones that can be made in an ideal world

they are certainly not encountered in real consumer electronics

We were talking car ECUs.

Were we ****

"Let me show you what it followed on from

* "hit it with the heel of
* your 'and'"

* Absolutely. First rule of electronic repair, hit it.
* if that doesn't work, hit it again, harder.
*
* When you are as experienced as me you will do this without prompting


Absolutely.

In our electronics lab where we maintain *very* expensive electronic and
electro/hydraulic equipment, whacking things with a rubber hammer is a
standard fault-finding technique.

The vast majority of faults are not fancy electronic failures.
90% are mechanical, connector, chaffed wire, etc.
Of the remaining 10% electronic problems, 90% of those are PSU-related.
Only a very small percentage is actual gubbins-failure."

Nice attempt at a swerve there

Not at all.

Which followed on from the OP. I'll let you lok up the title.

It was a good generalization anyway, not restricted to car ECUs in any
way.

MBQ