On Mon, 14 Jun 2010 19:49:22 +0100, 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

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

Tin whisker growth in germanium transistors?

Actually chips can and do fail after a period of working perfectly, as the
stresses of thermal cycling can break the welds on the fine wires
connecting the actual IC to its external pins.

SteveW