[SOLVED] How to tell if mb is bad or CPU or both.

[Murraywonna]

I'm so embarrassed, I can't believe I did this but.. I upgraded cpu cooler today, had mb out and when reinstalling it I accidentally plugged pcie plug into 8pin cpu plug and tried to boot. Nothing happened. While double checking all plugs I found the correct cpu power plug. After I switched plugs the fans spin, lights are on but it never beeps or boots. The screen stays on a gigabyte touch bios screen that shows options on bottom for"post screen" "bios setup/qflash" "xpress recovery 2" "boot menu " "qflash". I've never seen this screen before.
My board is gigabyte z68xp-ud3. My cpu is I7-2600k. I've used this setup for about 2years with no problems.
I realize I screwed up and I'm just trying to figure out what I need to replace. Also on the mb there are 4lights that say phase led and the colors are red, yellow, green, green. I tried all the options on the gigabyte screen and nothing happened until about 2 minutes selecting, I was able to get to bios once and everything seems as it always does. It recognized ram, hdd, cpu. The voltages all seemed correct and when I exited it restarted and went back to gigabyte bios screen I've never seen before today. Thank you if you took the time to read this and possibly help.

 

[taeioum]

It's hard to diagnose unless you have other parts to replace them with, one by one. If you had a different motherboard, you could swap everything over and check that.

The first thing I would do right now is take all the wiring from the motherboard completely (apart from the power button cables) and take the button-cell battery that is located between the two blue PCI-E slots. Let it sit like that for a little while. A good minute or so should do the trick, but I'd leave it out for about 10-15 minutes. Then only hook up the essential power cables and try to turn it on again.

I hope this would have the device function as normal. Do keep in mind that this will reset all of your BIOS settings such as overclocks, memory XML settings, et cetera.

 

[Jacob 51]

I'm so embarrassed, I can't believe I did this but.. I upgraded cpu cooler today, had mb out and when reinstalling it I accidentally plugged pcie plug into 8pin cpu plug and tried to boot. Nothing happened. While double checking all plugs I found the correct cpu power plug. After I switched plugs the fans spin, lights are on but it never beeps or boots. The screen stays on a gigabyte touch bios screen that shows options on bottom for"post screen" "bios setup/qflash" "xpress recovery 2" "boot menu " "qflash". I've never seen this screen before.
My board is gigabyte z68xp-ud3. My cpu is I7-2600k. I've used this setup for about 2years with no problems.
I realize I screwed up and I'm just trying to figure out what I need to replace. Also on the mb there are 4lights that say phase led and the colors are red, yellow, green, green. I tried all the options on the gigabyte screen and nothing happened until about 2 minutes selecting, I was able to get to bios once and everything seems as it always does. It recognized ram, hdd, cpu. The voltages all seemed correct and when I exited it restarted and went back to gigabyte bios screen I've never seen before today. Thank you if you took the time to read this and possibly help.

Probably a CPU error, since the computer does not post.
But still, it can be the motherboard.
Check the CPU's pins on the back of it. If you can see something burnt then that's your culprit