power problem

[gollo,]

Hi,
I'm with p5b-vm , 8800GTS, enermax liberty 500w.
Recently, on about 1 of every 3 cold boot-ups (pressing the power siwtch),
my system makes a series of beeps and my lcd remains powered off (amber light).
When this happens, I power off and on again and then the system loads normally.

Checked for leaking caps, didn't find any.
12v connector - 20 pin + 4 pin and aux cpu 12v are connected properly.
latest bios (1004)
when system loads, bios hardware monitor shows good constant voltage for vcore, 3.3v, 5v and 12v

What could be the problem? How can I diagnose?

Thanks

[zapionics<alt>]

Originally Posted by gollo,

Hi,
I'm with p5b-vm , 8800GTS, enermax liberty 500w.
Recently, on about 1 of every 3 cold boot-ups (pressing the power siwtch),
my system makes a series of beeps and my lcd remains powered off (amber light).
When this happens, I power off and on again and then the system loads normally.

...

First thing to check is that your vid card is properly seated in its slot.
A lot of systems will not boot up if the card is not in properly.
Just power off the system, remove the power cord and then remove the vid card and then re-insert it and make sure its firmly seated.

Post the result.

(oh btw, I'm assuming you're ok with this procedure but if you need help just post)

[gollo,]

Thanks,
Already checked that, removed and inserted the vid card again, it's firmly in place

[zapionics<alt>]

I'm assuming you have power plugged into the vid card... 6 pin?
If so have you change any BIOS settings recently, I'm thinking anything to do with the memory settings?

[ctal]

Besides the obvious suspects (power supply, mobo, memory, video card), I'd suggest checking out the possibility that the keyboard is the culprit. I've seen situations where a failing keyboard would apparently send out spurious signals that would cause symptoms similar to what you are describing.

Hopefully you have a different keyboard that you can temporarily swap in.

Otherwise, disconnect or remove everything that is not essential to getting into the bios screens, including memory other than one stick. If the problem goes away, replace things one-by-one to determine the cause. If the problem does not go away, at least you'll have narrowed it down somewhat.

Regards,
-- Al

[gollo,]

Thank you both for helping!

Yes, the 6-pin connector is plugged in properly.
As a matter of fact, I did add two 1gig mem sticks lately, but I persume they don't contribute to the issue, since it still happens without them (took them out).

I'll check the keyboard issue and post back new findings. If it doesn't help, I'll start eliminating out components...

Thanks again!

Daniel

[zapionics<alt>]

Originally Posted by gollo,

...
As a matter of fact, I did add two 1gig mem sticks lately, but I persume they don't contribute to the issue, since it still happens without them (took them out)...

Possibly some voltages/timings have changed... i'd recommend u try a load to defaults in the BIOS with the sticks in place... (take note of any special settings you may have)... also check that the vdimm is set correctly...

[gollo,]

Will do,

Thanks alot

[gollo,]

Well, it turns out that my mobo is quite ripped and not intended for oc'ers so I don't have control over Vdimm and so on.

Anyway, two days ago I pressed the power switch to turn my system on, and nothing happened. Tried a few more times... nothing.
Then I played a little bit with the AC power cable near the psu socket, and presto, the system turned on.
My best guess was that it was a faulty power cable, so I replaced it with a new one. So far, no problems.

Daniel