Built a new PC; worked fine until I replaced the CPU cooler. Now it refuses to post.

[Dankk]

I'll try to keep this detailed and concise. I have no idea what I could've done to cause this.

Just a week ago, I built a new PC. A nice FX-8350 machine with 16GB of RAM, a factory-OC'd MSI Twin Frozr 7870, and a Seasonic PSU. I tried to aim for quality components. This is my full build: http://secure.newegg.com/WishList/PublicWishDetail.aspx?WishListNumber=20837585

I put everything together, and the PC ran fine for a week. Basically no problems. However, the stock CPU cooler was pretty crappy (lots of noise, temps not so great), so I ordered a Cooler Master Hyper 212 Evo to replace it. This is the cooler I bought: http://www.newegg.com/Product/Produc...82E16835103099

I got the cooler today. Unplugged my PC and went to work installing it, doing everything as carefully and professionally as possible: Powered down and unplugged my PC, gently removed the stock cooler, cleaned the goo off the CPU with isopropyl alcohol and a soft cloth, screwed on the new backplate, put a dot of Arctic Silver 5 on the CPU, gently seated the new cooler and screwed in all 4 corners a little bit at a time. Secured the heatsink nice and firm, popped the fan on, and plugged it in. Pretty smooth installation process.

But... I plugged my PC back in, pressed the power button, and... nothing boots. The computer definitely receives power; the fans spin up and the LEDs come on. However, absolutely no posting happens. There's not even a video signal. The fans just sit there and whirr away while nothing actually happens on-screen.

Puzzling, right? I carefully re-seated my CPU, and then re-installed my cooler exactly the same as before. I also carefully re-seated my GPU and RAM to see if that would help. No dice. I power on the computer, but it still refuses to post or give a video signal.

What do you guys suggest? Keep in mind, this PC was working 100% fine last night. Installed a new cooler, and now something's totally borked. I've checked all my connections. Everything seems to be receiving power where it should be. Like I said, the cooler installation was trouble-free, and I can't think of anything I did that would've totally borked it.

Please give me suggestions, anything at all. Even if it's really simple. I might be overlooking something stupid, but I just can't think of anything. I reset the CMOS. I reset the battery. I tried unplugging the machine again and holding down the power button for 30 seconds, because that supposedly will discharge the PC of any static build-up or something. But that didn't help. I also don't believe I dropped anything inside the PC that would be causing a short. I'm extremely cognisant of things that I drop or misplace; I would've immediately noticed a screw being lost or dropped inside. (But then again I'm not 100% sure.)

I hope my motherboard isn't broken. 🙁

 

[denis280]

one question.i have a cooler like that.did you remove the plastic under???

 

[Steltek]

Did you check the power cables, particularly the 24 pin PSU motherboard connector, the CPU power cable, and the power cable to the video card, to ensure they are tightly seated? Also, did you remember to plug in the CPU fan leads from the heatsink fan to the correct motherboard header?

If you can't determine what the cause is, you'll need to go back to basics. Strip the entire system down to just motherboard, one memory module, and CPU. If it still won't boot or at least give you some beep codes, try booting with all the memory modules removed to see if it gives you a beep code response. You may also want to consider removing the motherboard entirely from the case, placing it on a piece of cardboard or a static bag outside the case, plug in the power supply and try to boot it up by grounding the switch pins with a screwdriver to eliminate the possibility of a grounding issue.

 

[lenjack]

If you didn't plug the heasink fan into the proper header, this can happen. The board will think you don't have a fan on the heatsink.

 

[Dankk]

Thanks for the advice, guys. The fan is definitely plugged into the correct header, and the plastic underneath the heatsink is certainly peeled off.

I discovered the source of the problem. Apparently my video card just went bad. It was probably defective from the start; and it just took a few days to manifest. I had a friend over today and we completely disassembled the PC, and tested each component one by one. When we swapped out the video card for a different one, it worked.

I am RMAing the card for a replacement on Newegg. Thanks again for the help.