For those with Car ABS and ECU problems;!..

[The Natural Philosopher]

Yes, teh failure of units is initially high, due to incorrect manufacturing: post that the failure modes are ageing, with mechanicals being the first to go, then usually electrolytics drying out as a second, and finally heats stress on circuitry that eventually breaks seals, or allows doping levels to migrate in over stressed semiconductors, and Phut.

BUT if well designed, 30-50 years is very achievable once production errors are accounted for.

mechanical issues like corrosion are far more likely to take stuff down than actual component failure.

[Man at B&Q]

Piece of p**s with the right equipment, even BGA replacement.

MBQ

[Man at B&Q]

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

[Man at B&Q]

MBQ

[Jim]

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:

[Mark]

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

[Tim Watts]

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

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

[Tim Watts]

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

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.

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]

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

digikey?

[tony sayer]

In article , Tim Watts scribeth thus

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:))..

[Bill]

In message , "Dave Plowman (News)" writes

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 :-(

>

[Dave Plowman (News)]

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

[tony sayer]

In article , Dave Plowman (News) scribeth thus

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...

[August West]

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

[dennis]

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.

[geoff]

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

That would make a good hen house, that would

[geoff]

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

[geoff]

So what, exactly, is your extensive experience?

[geoff]

In message , Tim Watts writes

Better tell Katie Price