From: Humphreys, David (david.humphreys_at_honeywell.com)
Date: Thu Oct 21 2004 - 11:17:07 PDT
Statistical mortality aside, modern electronic components are extremely
reliable. The main failure mode is operation outside of their parameters.
i.e. undersized or connected incorrectly.
Stuff failed in TV sets years ago because:
Parts were less reliable.
Voltages were much higher.
Tubes put out a lot of heat.
Today, except for the CRT or LCD backlight inverter circuit, voltage rails
rarely get above 12v. Heat is much less and component reliability is orders
of magnitude better.
By far the greatest failures of a 'modern' device like the Newton would be
due to 'tinkering' or operation outside the intended envelope.
The catasrophic failure of the transorb on the emate power input, for
example, is more likely to be incorrect operation/application than sporadic
self conbustion.
One likely theory is that the part was stressed during previous ownership.
I.E. they plugged an incorrect PSU into it. Perhaps it din't quite fail
right then but subsequntly the new owner quite legitimately plugs the
correct PSU in and BANG the part fails. These actions would lead one to
assume that since a good PSU was plugged in and it failed it must have been
a bad part.(which is correct but for entirely the wrong reason). Now we can
start the urban legend that emate will explode sooner or later - even if the
correct PSU is used.
Things are not always as they first seem.
I wish I had been this wise earlier in my career...
Regards,
PCBman
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