Martin wrote:
> ...
> BIOS 'PC Health' screen reports these voltages:
> CPU core - 1.58v
> +3.3v - between 3.21v and 3.26v averaging about 3.24v
> +5v - 5.15v
> +12v - 12.32v
>
> What do you all think then?
> ...

Assuming your motherboard monitor has been calibrated, then your 3.3
volts is too low while 5 & 12 are on and should not be so high. If one
voltage is too low and other tend high, then good reason to suspect
that power supply. What do those voltages do as peripherals (including
CD-Rom) are accessed simultaneously? If 3.3 drops even slightly, then
it is defective. To blame, with certainly, the power supply, we would
need an oscilloscope. Even if power supply is good, the 3.3 volt
numbers is too marginal for long term reliable service.

But again, above assumes numbers from motherboard have been
calibrated which is why a 3.5 digit multimeter would be a useful tool -
to calibrate the motherboard and to verify a new supply when installed.
Verified as multiple peripherals are accessed simultaneously as Kony
has suggests using bios health monitor menu page; else get numbers
using multimeter.

Temperature was not a valid suspect. CPU temperature must be
sufficiently low so that when room temperature increases 15 degrees C
(exceeds 100 degrees F), then CPU still does not exceed manufacturer
numbers (typically 90 degree C). Your temperature numbers were so
below as to be irrelevant to the problem.

Another reason to ignore those who recommend using an eraser on
electrical contacts: connectors are self cleaning. Any minimally
acceptable connector will be cleaned simply by 'breaking and remaking'.
Furthermore, design must have sufficient margin to make any 'dirty'
contact irrelevant. If using an eraser does anything useful, then
hardware is 100% defective.

Kony suggests power supply capacitors could be a reason for failure.
>From your numbers, that would be capacitors for that unacceptable 3.3
volts output.