Two different Mother Boards won't post

[Hyper_84]

I've been at this for days now and I don't know what else to try. I've got an E6750. I have a P5K-e and EP45-UD3P that I just ordered for a build for my girlfriend. Recently, my P5K-e stopped posting, entirely. But I could remove the CMOS battery and move the jumper and it would post fine. Everything was great until I shut down. I figured I'd try the same thing with the MB for my girlfriend's build and it also isn't posting. I've tried booting with 0,1 and 2 sticks of ram and nothing. No luck without the graphics cards. I'm afraid the CPU might be toast, but I don't understand why it would work fine if I clear the CMOS on the P5K-e, but not if I clear the CMOS on the EP45-UD3P

 

[cmichael138]

What are the rest of your specs?

 

[masterasia]

It could be a bad CPU. I've had that happen to me already.

 

[Hyper_84]

I've got a corsair HW620, 2x1GB DDR2 800 Crucial Ballistix, Sapphire HD4870 512MB. Since it's two different motherboards, I have to imagine it's the RAM, CPU or PSU.

 

[capt_taco]

What happens when you turn on the system? Does it power up briefly and then shut off? Does it crash and beep at you? Does everything power on like the computer is running, but there's no video? Do any lights or fans come on? Or does it just not turn on at all?

 

[Hyper_84]

All of the lights and fans come on, even the CPU fan. The GA-EP45-UD3P would go into a boot cycle, but never displaying the post message. The P5K-e is back in for now, and so long as I pull the CMOS battery and clear the BIOS it will post and I can run everything fine, until the next power cycle. I just can't understand what clearing the BIOS would do to make the P5K-e work. I'm still waiting on a new PSU to test and some new RAM.

 

[jsc]

Our standard checklist and troubleshooting thread:
http://www.tomshardware.com/forum/261145-31-read-posting-boot-problems

 

[Hyper_84]

I'm kind of doubting the CPU. I have the box running right now. I can play HD videos and play Torchlight without any trouble. My multimeter doesn't seem to be working right now, so I'm having a hard time checking the PSU.

 

[capt_taco]

OK, first of all, I think you need to ignore whatever is happening with the EP45-UD3P board for now. When you switch motherboards and keep the same hard drive, the system is pretty likely to not boot anyway. The drivers for the old board will still be on it and causing havoc. So unless you have another hard drive you can use for that, with a clean install of Windows, I don't think it'll be a reliable way to troubleshoot the rest of your components.

It's weird that your system will work the first time after the BIOS is reset but fail again the next time. It sounds almost as if the default settings are OK, but something is causing the system to "forget" them when it powers down. I wonder if the BIOS has somehow become corrupted, or the version needs to be updated. It wouldn't hurt to try downloading the latest BIOS and motherboard drivers and installing them on that machine.

You might also try replacing the battery itself. A dead or dying battery can sometimes cause CMOS errors -- including corruption errors, in fact.

In fact, since your computer looks like it's 2-3 years old, I'd say that adds significantly to the chance the battery is gone. If nothing else, this might be a good opportunity to replace it anyway. Try that and see if it'll hold past one boot.

 

[Hyper_84]

I replaced the CMOS battery first, but to no avail. the EP45-UD3P i tried to boot without any SATA devices connected, so I doubt the harddrive has anything to do with it. I'll try reloading the bios and see how that goes. Thanks.

 

[Hyper_84]

Update: I just identified the issue. The power supply was the culprit. The 12V and 5V power was fine, but the 3.3V just wasn't good enough. For whatever reason the P5K-e can be coaxed into booting by removing the CMOS battery and clearing the bios. Now I need a new PSU for a P180. Any suggestions?