PSU but
Percentage wise, your voltages are still in the "normal" range,
although I'd want to verify the voltages with a multimeter.
A failure to POST could have any number of root causes. One
reason is if the Vcore regulator circuit abruptly shuts down
when the system is powered up. One model of motherboard had
issues with Antec Truepower supplies, and the problem was
corrected in subsequent production by changing some component
value. Otherwise, it could be just about any component sitting
on a system bus, that could throw a wrench in the works.
If you had just CPU, memory, video card, keyboard/mouse, does
it work any better ? Try testing with just one DIMM at a time.
If you switch power supplies, try using a different brand of
supply.
In terms of gathering information, if the motherboard had
Vocal POST, you could listen for any error message, as that
might hint at the source of the problem. There is also a
debugging card you can get, that plugs into a PCI slot, and
it intercepts writes to port 80, and displays them on a
two digit LED display. The BIOS companies have lists of
which BIOS routine is running, when a particular number
is being displayed. A port 80 POST card used to cost $100,
but some Ebay sellers have sold them for $20, as they really
don't have a lot of expensive chips on the card.
Here is an example of a diagnostic PCI POST card:
http://cgi.ebay.com/PC-PCI-Motherbo...6791398721QQcategoryZ1244QQrdZ1QQcmdZViewItem
The main value of a PCI POST card, is it can show you whether
the processor got to execute any code or not. Another device
that provides a little info like that, is the LED displays
on some expensive memories. A failure to see any acivity on
the DIMM's LED display can be used to imply that the BIOS code
never tried to initialize memory.
In terms of buying a good power supply for your computer, you
should be buying them based on the rating information printed
on the label on the side. Many of the cheaper supplies give
an exaggerated total power rating for the supply - if,
for example, the supply doesn't offer a minimum of 12V@15A
output, I would expect problems with a P4 based system. There
were some old 500W supplies (when 500 watters first came out),
that only offered 12V@10A. Such supplies were only usable on
AthlonXP systems, where the +5V was the main source of
motherboard power. On my P4C800-E Deluxe, using four DIMMs,
my measured consumption is
[email protected] amps,
[email protected] amps, and
12V@6amps. This does not include the video card, or the disk
drives. In my case, it is meant to show that not much +5V is
used, a moderate amount of 3.3V, and the +12V can be calculated
based on the model of processor being used, at a site like this:
http://takaman.jp/D/?english
I only have a 2.8GHz Northwood, so don't use that much +12V.
Paul
