No POST after CPU change (Phenom II X4 955)

[Jasso]

Just updated my desktop by changing AMD Athlon II X4 620 to AMD Phenom II X4 955. I've also added extra fan to my Cooler Master Hyper TX3 heatsink and plugged it to chassis fan plug on the mobo. My mobo is Asus M4A785D-M PRO with BIOS ver 0806.

Problem was that when starting the computer again after changing CPU, everything powers up (fans, GPU, SSD, HDDs), but no POST. Tried resetting CMOS with no luck.
Unplugged the new fan and USB card reader (which had previously causing issues) from the mobo. Another reset to CMOS and got to BIOS after restarting. Updated date & time, but then the whole thing froze. Restarted after waiting for a while, but again no POST. Tried resetting CMOS, but didn't work.

I'm stuck, please help!

I was very careful and used ESD strap and ESD cloves while changing the CPU.

 

[CDdude55]

Put the Athlon back in and if it boots then it most likely needs a BIOS update. On the website for your board it describes three different revisions for the 955, i'd try updating to the 0704 and see if it boots fine then.

 

[Jasso]

Thanks for quick replies, much appreciated!

Just popped the Athlon CPU back in and resetted CMOS. Fired the computer up, but no POST. Everything is now the same way it used to be before starting the whole CPU changing operation, but still nothing. Tried unplugging GPU and used the D-SUB on the mobo, but nothing. Noticed that there is no power to USB keyboard or mouse, but reset button on the front the computer is working.

 

[Jasso]

Yup, already double checked all the cables and ram. No luck. All I can think of is to check the mobo for any loose components or short circuits etc.

 

[Jasso]

Just disassembled the whole thing, checked the mobo visually, but nothing seems to be missing as far as I know, nor I found any component at the bottom of the computer case. No burn mark etc on the mobo or any components.

Put it back together, but only assembled Athlon CPU, primary SSD, two RAMs and CPU cooler. Resetted CMOS and plugged power cable back in. Started the rig and miracle happened, it posted to BIOS. Set date/time and booted to Win7. Downloaded the latest BIOS version and flashed it with EZ Flash2 from 0806 to 1001 without any problems. Rebooted back to Windows and made sure that the OS also recognized the new BIOS version. Everything seemed to be in order, so I decided to reply to this thread that so far so good...

Computer froze after a couple of minutes and I had no choice than to reboot. Result: back to the square one, hard drives and fans are working, but again, no POST... Any suggestions? Could some of the transistors be malfunctioning under a stress, or stop working after reaching a certain heat level?

 

[Jasso]

Anyone? Could I have somehow ruined my mobo, and is there a way to check this?

 

[Gaidax]

No idea, everything can be. My suggestion - just go take a drink and rest a bit, you are probably stressed and it's a recipe for more fuck-ups.

After you have aired your head with fresh air - try do disassemble stuff again and reassemble with minimum stuff in - like only 1 memory stick, Video Card and CPU in and that's it, no SSD, no Hard Drive, no DVD, no nothing else.

This at the very least should still give you POST and BIOS access. You get POST and BIOS setup? Good, add more pieces of hardware.

Not getting POST? Check carefully if you did not bend CPU pins and try another memory stick or port.

 

[Jasso]

Thanks for the help, it seems that my mobo didn't like the changing of CPUs. Did as Gaidax suggested, but no luck. No POST even with a minimum setup, tries several memory sticks to different ports too. Nothing extra visible on the mobo. No bend pins on either CPUs.

 

[Jasso]

Just measured how much power the PSU is outputting to the mobo (24+4+4 connectors). Seems to be in the specs. Even tried several times resetting the PSU in between measuring. Going to find another mobo and test that.

 

[DanielC23]

Does it appear to you that your CPU is more than likely DOA?

 

[Jasso]

Nope, since the old CPU is not working either.

 

[rush21hit]

I also has the exact problem as OP had.

I'm gonna tell you the whole story here, please bear with me.

At first I have this old beast from my buddy and tested it on his motherboard, everything was okay. I even play some Skyrim on it for some time until my friend called his motherboard back to be sold. And then leave the CPU to me. That was a year ago.

A few months back, I purchase a second hand motherboard from a guy. It was Biostar A780L3B, which was so cheap, I even bought it along with his CPU still installed, X2 270. When this guy came to my house with his item, we tested it for some time to make sure it works properly. The motherboard and CPU warrant still have about 2 years, quite new stuff. So, when I installed my X4 955 to this motherboard, witnessed by the seller too, it never even POST BIOS. Then we revert it back to the X2, it can POST.

Confused, I did what was I thought the right thing to do;

-Get a better PSU(borrowed a Seasonic 500Watt from my buddy across the street) not because I didn't believe on my own PSU (CX450) but just want to see if there will be different outcome, good or ill.
-Borrowed a single stick Team Elite's RAM from the seller, 2GB 1333 model.
-Tuck off my GPU.
-Retry the whole process.

Still no POST.

Then I update the firmware, as a last options.

Yet, no POST with the X4. The X2 on the other hand, run just fine. With or without firmware updates.

I told my buddy that was given me the X4 what happen, he came to my house pretty quick. The CPU has some emotional meaning to him, apparently.

Then all 4 of us trying to figure out what is happening. At first my buddy blame on how I stored, to me reminding him that it was him that wrap the thing up, I simply put it on my closet along with my other boxes of PC stuff.

No pin was bent. No apparent physical damage.

tl;dr my X4 955 died for unknown reason, I still stuck on X2 270 to this day.

I was suggested to another option though; oven the thing. The thought shudders me. I just leave it be.