In message
, Man
at B&Q writes
On Jun 15, 11:02*pm, geoff wrote:
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

percentage is actual gubbins-failure.

I like that breakdown, it's about right. I'd add that a lot
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,

Care to provide proof of that?

I'll accept that things are not designed to last but you seem to imply
malice.

Well - for starters

sticking to boiler pcbs

the real killer of pcbs is fans - the back emf destroying the contacts
of the relay driving it.
A snubber network, costing less than pence would mitigate the problem

also, e.g. Potterton use a smaller relay to drive fans than they used to
do

there are two possibilities, mad or malicious

I could go on, but I have to go to a residents meeting in a few minutes

laters

--
geoff