Take the 2-minute tour ×
Super User is a question and answer site for computer enthusiasts and power users. It's 100% free, no registration required.

I tried to upgrade my PC with a CPU change. The motherboard is a Gigabyte P35-DS3L, the old CPU is Core 2 Duo E6550, the new one is a Core 2 Quad Q9400.

I had to to take out the graphics card and two of my four ram bars to reach the mounting of the CPU cooler, but all in all the change was no big problem.

Now, when I switch on the PC, it is powering, but nothing happens on screen. Sometimes it seems to get stuck in boot loop, sometimes it just sits there and does nothing and sometimes it switches completely off after some boot tries.

So I decided to put in the old CPU again and look, if I have to do a BIOS update. And now I have the same problem with the old CPU.

My next step will be to rip all apart and clean everything and then build it up from scratch to make sure, everything is in the right place and nothing is loose.

Any other ideas, what could be causing this problem?

Edit Problem solved. I reset the BIOS as suggested by @FrankThomas and then updated the BIOS as suggested by @Ramhound. Now I'm rocking on four cores. I will see, if the power supply is good enough for the new setup. Thank you guys for all the comments.

share|improve this question
1  
Obvious question, but have you made 100% sure you connected all cables for power and (CPU) fans, AND connected them in the right way ? I once gave myself heaps of trouble by connecting a power supply cable upside down (I assumed this is not possible, but now I know it is). –  pleinolijf Dec 4 '12 at 13:42
1  
have you confirmed that your 4-pin v12 rail is plugged in near the CPU? Also have your tried a resetting the BIOS since you put the old CPU back in? your Mobo manual should tell you how. usually a little button or a pair of jumpers to bridge. –  Frank Thomas Dec 4 '12 at 13:45
1  
Have you confirmed the BIOS revision currently loaded supports the CPU you are trying to use? Unless you can confirm this its unlikely we can assist. –  Ramhound Dec 4 '12 at 13:52
    
@pleinolijf: yes, I'm pretty sure, I had everything plugged in right. I checked it two times. –  henrik Dec 4 '12 at 14:25
    
I didn't think about resetting the BIOS. Currently I have the whole system apart, as I planned before. I also took out the battery to reset the CMOS. If this fixes the problem with my old CPU, I'm going to check for support of the new CPU and if I have to update the BIOS to support it. –  henrik Dec 4 '12 at 14:29

1 Answer 1

Problem solved. I reset the BIOS as suggested by @FrankThomas and then updated the BIOS as suggested by @Ramhound. Now I'm rocking on four cores. I will see, if the power supply is good enough for the new setup. Thank you guys for all the comments.

share|improve this answer

Your Answer

 
discard

By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.