Am I missing something?

Iron_Hoss · 07-30-2010 05:24 AM

Turned on my computer the other day and got nothing on the screen. Fans spun up and LED's lit, but screen remained totally blank, and no Bios beeps. Now the other day the computer was working, and I had not made any changes on it that can think of.

I've checked and the screen is fine, works on another computer,
swapped the vid card from the non working computer to another working one and got a picture with that vid card.
Put the vid card from a working comp in the non working one and still no picture.
Tried different PCI express slots on the non working computer and still a blank screen.

which makes me think this is a mobo issue.

Anything else I should check?

@IronHoss
@Payamma Gurl
I'm sorry that your crew was stupid enough to fire on a station filled with a quarter million civilians, including your own people. And I'm sorry I waited as long as I did before I blew them all straight to hell. ~Sheridan, The Fall of Night

Partsman · 07-30-2010 05:41 AM

Fans usually run off the 12V rail, but the mobo needs the 5V supply to be working. Sounds like it may be either a power supply, mobo, or CPU problem.

Iron_Hoss · 07-30-2010 05:48 AM

CPU would start to post wouldn't it?

@IronHoss
@Payamma Gurl
I'm sorry that your crew was stupid enough to fire on a station filled with a quarter million civilians, including your own people. And I'm sorry I waited as long as I did before I blew them all straight to hell. ~Sheridan, The Fall of Night

Partsman · 07-30-2010 05:52 AM

Not if it was a catastrophic failure, involving incoming power. Just curious, are the fans for the power supply clean and the fan and fins for the CPU clean?

Mirai_Teirusu · 07-30-2010 08:22 AM

To me, it does sound like your motherboard, but its still possible that your power supply could be a fault. When diagnosing a problem like this, I always try the power supply first, just to make sure.

Since you said you have another computer at home, its not too difficult to remove the power supply from it, then use it to try to POST your non-working computer. Or, you could buy a power supply from a store, temporary, and use it instead for this purpose. (During a test like this, I'd always unplug components from the motherboard and power supply that are not needed for POSTing: All drives, extra add-on cards like sound and Wi-Fi cards, etc. )

If your computer still doesn't POST with a working power supply, then yes, its most likely your motherboard, and depending on how old it is, you might not be able to find an exact replacement. (At least something that matches your CPU and memory!) So, be prepared to buy a new motherboard, CPU, and memory; in that case.

Iron_Hoss · 07-30-2010 08:55 AM

Yeah, I didn't think to test the PSU, as that's not where i usually skimp, I just assumed it was fine when the things spun up. That and the case on the non working comp is a real hassle to work on. I might have a PSU on a Linux system I could use to test (we moved recently, not sure what is in storage and whatnot).

Installed new case fans a few months ago and cleaned off the vanes and fans of the CPU heatsink then. This case sits on the shelf at eye level, so it's not picking up a lot.

@IronHoss
@Payamma Gurl
I'm sorry that your crew was stupid enough to fire on a station filled with a quarter million civilians, including your own people. And I'm sorry I waited as long as I did before I blew them all straight to hell. ~Sheridan, The Fall of Night

Apogee · 07-30-2010 09:12 AM

I had the exact same symptoms not long ago. I even went through the same process, monitor, video card, power, motherboard, etc. It turned out to be a bad RAM stick (had dual channel, 2GB from Corsair). When I tried to boot with a single stick the computer would work. I tested each stick and found the one that was dead. Also note, there was no bios alarm on boot when both sticks were installed (when just the bad one was installed I got the alarm). I replaced the memory and have been running fine ever since.

Hope this helps.

edit: B5 rules!

Iron_Hoss · 07-30-2010 11:21 AM

Well that's annoying.

Checked voltages from the PSU/mobo connector and everything was fine, pulled a stick of RAM, and I heard a Bios beep when booted. Set the RAM I pulled out, and a BIOS beep again. So no changes and I'm up and running. Only thing I can think is that one of the RAM sticks wasn't set well.

Thanks for the help guys.

Hoss

@IronHoss
@Payamma Gurl
I'm sorry that your crew was stupid enough to fire on a station filled with a quarter million civilians, including your own people. And I'm sorry I waited as long as I did before I blew them all straight to hell. ~Sheridan, The Fall of Night