Computer won't turn on

[Jack Bruss]

My sons computer just started acting up. It's a P4 2.4g on an Asus P4P8X
865P mb that we built last summer, and it's worked fine up til now.
When he turns it on, the fans go on for just a split second, and then
everything shuts down and nothing happens.

The case is a cheap Raidmax that was only $37 including the 350W power
supply, so we're thinking maybe the power supply is bad.

Is there some way to check that short of putting in a new one and trying
it?

Any other thoughts on what the problem could be would be greatly
appreciated.

Thanks,

Jack

 

[Alex]

I've had the same thing twice. Both times it was a dodgy psu. Try and get
hold of another one to test though, before you fork out on a new one

 

[Noozer]

Almost definately the PSU with the mainboard being second...

 

[DaveW]

You really do need to put a working good quality power supply into the case
to see if it's working. If the power supply is OK then the motherboard is
probably bad.

 

[w_tom]

No one can answer your question with information as
provided. However don't waste time complicating the issue by
part swapping; wildly replacing power supplies. Start by
confirming integrity of that power supply and related
circuits. Procedure done in minutes is provided in "Computer
doesn't start at all" in alt.comp.hardware on 10 Jan 2004 or
http://tinyurl.com/2t69q

IOW determine if problem is power switch, motherboard
controller, or power supply. Three critical voltages are 3.3,
5, and 12 volts on orange, red, and yellow wires. If any one
voltage does not rise, then all other voltage will then be
removed a split second later. Sound familiar? Procedure
would make 'reason for failure' obvious if one of those
voltages is being shorted or is defective.

Once power supply integrity is confirmed (without buying
more power supplies or wasting more time swapping), then move
on to other possible reasons for failure. A simple and quick
process of eliminating the usual suspects. Power supply is
the first suspect investigated because a bad power supply /
motherboard / power switch system can make further diagnosis
impossible.

Then learn about power supplies - good and bad - from
another thread in the alt.comp.hardware.pc-homebuilt
newsgroup entitled "GOOD powersupply for under $40?" starting
21 Jan 2004.

 

[kony]

My sons computer just started acting up. It's a P4 2.4g on an Asus P4P8X
865P mb that we built last summer, and it's worked fine up til now.
When he turns it on, the fans go on for just a split second, and then
everything shuts down and nothing happens.

The case is a cheap Raidmax that was only $37 including the 350W power
supply, so we're thinking maybe the power supply is bad.

Is there some way to check that short of putting in a new one and trying
it?

Any other thoughts on what the problem could be would be greatly
appreciated.

Thanks,

Jack

The Raidmax power supply is bad, as-in, bad even if it still works as
well as when new... bad enough that if it hasn't killed your
motherboard yet, it may easily do so. Even if the power supply still
works but the motherboard is dead, the power supply should be
replaced. It makes sense to go ahead and do that now and maybe you're
lucky and it was only the power supply.

You might unplug the power supply from AC for a few minutes, then open
it... very likely the output filter capacitors are vented, but that
unit isn't worth repairing even if you have the skill and parts to do
so.

 

[Trent©]

My sons computer just started acting up. It's a P4 2.4g on an Asus P4P8X
865P mb that we built last summer, and it's worked fine up til now.
When he turns it on, the fans go on for just a split second, and then
everything shuts down and nothing happens.

Do you get any kind of a POST at all on the screen?

The case is a cheap Raidmax that was only $37 including the 350W power
supply, so we're thinking maybe the power supply is bad.

Is there some way to check that short of putting in a new one and trying
it?

See the other posts for this.

Any other thoughts on what the problem could be would be greatly
appreciated.

Take the cover off...look for any obvious clues. Especially check to
see that the CPU heat sink fan is running.

Good luck.


Have a nice week...

Trent

If the cheese isn't yours...its Nacho cheese, man!