My motherboard is dead?

mstwntd

Distinguished
Mar 12, 2010
22
0
18,510
Hello all,
I came home a couple days ago and found my CPU fan not running, and not getting any video on my monitor. Uh oh, immediately shut it off. When on, the mobo lights work, everything fires up besides the cpu fan and there is no video. Here is what I have tried:

RAM in all kinds of different configurations
A different PSU hooked up to the MB
Different 4 pin headers for the cpu fan
Different heatsink fans in both 4 pin headers (My ram cooler was in the other 4 pin - which also wasnt spinning)
A different video card in the slot (still no dice)

I've pretty much narrowed it down to the mobo or the PSU (possibly overvolted stuff? 600W OCZ Modular)
Video card is a brand new 6870.

I ordered a new ram/cpu/mobo combo since it was time for an upgrade anyway, but I'd like to figure out what is dead so I can sell what works. I'm afraid to plug new stuff into my current PSU however, I don't know if it has gone insane.

Any thoughts?
 
I'd check the 4 pin (or 8) ATX 12V connector. I recently had one that burned up on a build, I did have to replace the motherboard and the connector was burned. It remains to be seen if there was any damage to the PSU but I would guess the mobo before the PSU. If you have a spare mobo to test the PSU with I would do that before plugging a new board in.
 

mstwntd

Distinguished
Mar 12, 2010
22
0
18,510
That is what I don't get...it worked when I left and didn't when I got back. The mobo and all cables don't have any sign of defect at all.

I just cleaned off all the old TP from the cpu cooler and cpu. If the chip works tomorrow I suppose I will try to piece it together one last time.

I will have to throw my PSU on the other computer, hoping it doesn't blow it up too. I did the paperclip trick and it worked fine, but I guess that won't tell me if it's overvolting something.
 


The thermal paste shouldn't have anything to do with this. Only if you recently did something with the CPU and didn't get it mounted in the socket correctly.

You tried another PSU, that was a nogo. So while we can't say whether the first PSU is good or not, what we can say is that the motherboard in its current state is not working. Did you pull the CPU and inspect it? I had a mobo burn up my CPU, the socket fried several pins-in fact it was so hot that it fused 3 pins on the CPU together. Had to RMA the board and buy a new processor. Nothing wrong with the PSU--that time.

Look, any number of things could have happened that's the way it goes with electronics. One bad thing can cause a whole string of other problems. A bad PSU could possibly fry your mobo, CPU, ram, video card, etc. So for sure the mobo in its current state is not working for whatever reason. The PSU is suspect because of the power issues, like the CPU fan not spinning up.

Have you taken a look at the troubleshooting sticky? I recommend you read that thoroughly and be careful about hooking too much up to that OCZ PSU until you know whether its good or not.

http://www.tomshardware.com/forum/261145-31-perform-steps-posting-post-boot-video-problems

Its important to take the system down to the bare minimum so you can eliminate components as the culprit.
 

mstwntd

Distinguished
Mar 12, 2010
22
0
18,510
I guess I said that wrong. I took the CPU and heat sink apart, then realized it would have been smart to piece it back together outside the case. I'll do so tomorrow after I test the CPU to see if it's working.

I've looked over every part and nothing is different than how it looked before.

My best guess has to be the mobo if the fan slots don't work.
 

mstwntd

Distinguished
Mar 12, 2010
22
0
18,510
Well stupid me didn't realize that my mother's mobo is too old (socket 775 still, but not compatible) for my C2Q. I guess I will have to wait until I find someone with a Core 2 Duo/Quad PC to test mine out with.