Power supply problems (was: Machine Check Exception)

hanzl at noel.feld.cvut.cz hanzl at noel.feld.cvut.cz
Tue Apr 15 05:49:52 EDT 2003

> Does anyone know if a power supply can cause a machine check exception

Power supply can probably cause all sorts of weird problems, with
variety similar to RAM problems - problem can surface just anywhere
and resemble other hardware or software problem to such an extent that
usual diagnostic steps like replacing hardware and software components
clearly indicate that something else is faulty, replacing that
'faulty' component seems to fix it but later on problems reoccur.

In another words, if your power supply works near the limits, problems
may be observed just on few nodes in the cluster (or on a single node)
and there may be just certain hardware/software/environmental
circumstances which trigger the problem.

I've seen certain indications that these days power supply can cause
more headaches than before:

- note from Abit tech staff saying that certain power supplies send
POWER_GOOD 'too early', meaning before on-board power conversion
circuits had time to stabilise

- overclockers are starting to take power supply more seriously.
(However stupid overclocking is, their web sites gives good
indication which parts of hardware work near to the limits.)

- note that certain Abit BIOS upgrade fixes PSU problems

- many problems with Abit IT7 MAX2 and 300W PSU I've encountered

- fact that modern PSU is under software control and hardware control
of that part of mainboard which gets standby power, opening new
possibilities for intermixing PSU/hardware/software problems.

Most of my experience is Abit-related but may be general I am



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