MB won't post after upgrading cpu's.

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johnsonma

johnsonma

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Here is my build:

MB: ASUS P8Z68 DELUXE/GEN3
CPU: Intel 3570k
GPU: Nvidia 690
RAM: 8GB gskill ripjaws
PSU: xfx pro 750W 80plus silver



The first thing I did in this installation was flash my bios so that my motherboard would support the new processor (which is a 3570k). It flashed fine and I booted into windows and made sure everything was working good.

Step two was to turn off the machine and switch the cpu's. This went fine, did all the normal thermal compound cleaning and reapplied it to the new cpu. Put the cooler back on and tried booting, everything booted up but the motherboard wouldn't post and it gave me a QR code of 55, which according to my motherboard manual means that no memory is installed.

First i tried using the memtest on the motherboard itself, this has helped me before but didn't seem to work this time. Tried resetting the cmos, also didn't work. Reseated the cpu but that didn't work either. Finally tried switching the old cpu back in and ended up with the same issue.

I then started mix and matching my ram sticks in the different slots. I finally got the MB to post when plugging just one of the sticks into the fourth slot. It won't work in the other 3 and the other stick won't work in any of the slots.

I'm leaning towards a bios issue but not entirely sure.
 
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goonbar79

goonbar79

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You are still in the game as long as the mobo boots at all. I would try the following using the 1 ram slot that works + the old CPU.

1. flash to the latest BIOS. I noticed that this mobo has different version for OS type (win7,8 vs winxp), so install win7 one. If this doesn't help, revert back to the working good BIOS that you have used previously.

2. manually set ram timing & voltage in BIOS to exactly match the rating for your ram sets. Then, try to see if you can boot with 2 sticks, then 3, then 4. If any sets are different make/model, I would not mix it up to eliminate ANY compatibility issue possibilities. If you can't make this happen with 2 different BIOS versions, you have a mobo hardware problem, so I would send it in for RMA.

3. If you can get 2 or 4 sets of ram to post, assuming these are matching set, run memtest86 for at least 5 passes. If you get any issues, I would test each ram separately to rule out individual ram stick issue.
 
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johnsonma

johnsonma

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Well, I tired everything you said with no success. I also had new ram ordered when this issue arose and when I popped those in they didn't work either. I'm guessing I bent one of the pins on the cpus socket. Is it hard to bend those back into place? I have never tried.

Also on a side note, on an asus forum they said the 55 code usually points to a cpu cooler that is not seated properly. I will try to reapply the cooler first to see if that helps.

 
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goonbar79

goonbar79

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Does the system boot at all, or not even once? A wrongly installed cooler should not cause boot problems, as the the cooler is not "required" to boot the system, only that once the heat starts to go up (since no heatsink to dissipate it), the system will shut down pretty quickly. If the mobo requires it, probably just the cpu fan connector is needed to be plugged in.

If you checked everything, and still nothing boots, its either psu, cpu, or mobo problem (assuming you have several ram sticks and tried each one at different slots). If the psu is a brand psu that is fairly new, the chances of failure is pretty low. Mobo has high chance of failures, due to the complexity of its build and small components that make up the board, much more so than a bad cpu. BUT a bent cpu pin is pretty common to (builder error, or bad luck), so it is a good idea to ALWAY reseat cpu (check the pins while at it), & ram if no boot issue persists.

FYI, I usually troubleshoot such issues outside the case using manual on/off method using flat tip screwdriver instead of case front power button connector/header. That was, I can rule out any case front header /button issues, and the process is much easier to do in the open. Afterward, I install heatsink once the "beep" has been confirmed,
 
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thenh813

thenh813

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CPU pins bend very easily and are made out of gold or are gold plated as is all the wiring inside them so for part of the large price on new CPUs :)
All you really have to do is straighten the ben pins with a tweezers very carefully till they are straingt. Onec I accidentally bent half the pins on a CPU over because it slipped out as I was pusing down on the heatsink spreading the paste. It worked perfectly fine after bending them all back. Make sure the fan is plugged in right and working and its pins arent bent over either. Some motherboards wont boot if a fan is not detected to keep the CPU from burning/melting.
 
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johnsonma

johnsonma

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I can get it to boot just fine, only 1 of the ram slots works though(with all 4 sticks). If I put a single stick(tried all 4) in any other slot it won't post. Also if i put one in another slot and one in the working slot it will not post. It runs perfectly fine with the one slot too. I can play games with no issues (other then i'm running 4gb of ram lol).

I tried multiple bios versions to no avail, also i updated the bios and it worked fine, then after the cpu switch i ran into the problem. I'm guessing during the cpu installation I messed up a pin haha.

 
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thenh813

thenh813

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From what know now about the problem, either there is a bent pin on the CPU or the MB has a failed Chipset/RAM Controller.

About the quote in your signature that I just noticed LOL thats very funny.
 
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johnsonma

johnsonma

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It was a bent cpu pin(s) (quite a few actually, whoops). Got all of them fixed but one tricky one that ended up falling out of the cpu socket. Somehow it still works, I'm guessing it was a grounding pin? All my ram slots work now though and the new cpu is in as well.

I ordered a new motherboard though, I don't really want to test what might happen with a pin missing.
 
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thenh813

thenh813

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Great you got it solved, but not so great you broke a pin.
It probabally was a ground or some other flow control pin which others like it can take up its job. If it works on this MB it will probabally work on the new one [not 100% guaranteeing it though]. Wish you good luck!
 
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