Gigabyte P55A-UD3 problem

[achaye]

Hello,

I have a Gigabyte P55A-UD3 (rev1.0) motherboard that has a weird boot problem.

If the computer has been turned off for awhile (probably over two hours), and I press the power button, the power light and HDD light on the case front panel lights up briefly, then one of two things can happen:

Either the computer stays on (the lights are on) but the screen is blank.

Or, the computer resets by itself, and is able to post to BIOS, but with settings set to a temporary fail-safe default (the BIOS settings are not erased at all, simply going into the BIOS and "Exit with Save" returns your settings).

This is really weird because it will happen ONLY if the computer has been off for awhile. If I shut down from Windows, and press the power button shortly afterwards, the computer will boot perfectly fine and will be as solid as a rock (passes 10+ hours of Memtest86+, IntelBurnTest, various Everest tests, etc).

Can someone help me out?

My specs are:
BIOS: F11, AHCI mode, HPET set to 64bit (for Win7 x64)
GPU: XFX HD 5870 587X-ZNFV video card on PCI-e 2.0 slot
RAM: 4x2GB Mushkin Ridgeback @ XMP-1600 profile (6-8-6-24 1.65V)
Sound: Asus Xonar Essence ST on PCI slot
PSU: SeaSonic X750 Gold 750W PSU
WD VelociRaptor 600GB SATA 6.0Gb/s connected on SATA3 slot
WD 2TB SATA2 drive connected to SATA2 slot
Pioneer BDR-205BKS Blu-ray burner connected to SATA2 slot
Antec Solo Black/Silver Steel ATX Mid Tower

 

[Maziar]

The title of this topic has been edited by Maziar

 

[ekoostik]

CPU?

Lots of people stuggle with "cold boot" issues. Try turning off XMP. Or try setting QPI/Vtt to 1.15V. Or both.

 

[achaye]

I ended up having many back and forth with the Gigabyte support people, and tried many things that they suggested, ending with attempting the boot with just CPU, one stick of RAM, and the video card plugged in. Same thing happened.

Next, they suggested swapping power supplies to see if it's a PSU problem, but I do not have any spare power supplies. I doubt it is a PSU problem though, as I've searched all over Google for problems with the Seasonic X750, and could not really find any; it must be quite a robust power supply with low rates of failure. On the other hand, from just Newegg alone, I've read about very similar booting problems.

Anyone have any other suggestions? I feel like I'm at my luck's end, and will probably send this back to the manufacturer under warranty for a replacement.

 

[ekoostik]

What CPU do you have?

Try turning off XMP. Or try setting QPI/Vtt to 1.15V. Or try both.

 

[achaye]

I have a Core i7 875K at stock 2.93GHz, with the QPI set to 1.15V; RAM also back to default 1.5V and 9 latency. Still has the same problem.

I believe I'm just going to live with it; this ONLY happens when I leave the computer off for prolonged periods and then turning it on. This has me to believe that it may have something to do with the capacitors not charging fast enough.