Hey, everyone, I've recently built a new computer and my motherboard will only post if I have RAM in slots 3 or 4. It will not post if there is any RAM in slots 1 and 2. Dual channel configuration also does not work.
Motherboard is a Biostar TZ77XE4
CPU: Intel Core i5-2500k LGA 1155
RAM is Corsair Vengeance 4gb sticks.
Hi, It looks like a CPU bent pins issue, assuming you've properly installed the RAM modules in the slots and there is no extra standoff shorting the board. If you decide to uninstall the CPU, use a magnifying glass for inspecting the pins. Or take a high res picture.
I've had it breadboarded today, so it's not a shorting issue. The motherboard reads the CPU in the BIOS when I get it to post with RAM in slot 3 or 4 and the the pins don't look bent to me. And it reads the RAM correctly when it boots with RAM in slot 3 or 4. I'm also guessing I don't have a buzzer on this motherboard because I don't get any beeps when I have no RAM inserted. There are BIOS post codes on this motherboard. I always get the code 55 if I have RAM in either slot 1 or 2. I checked the motherboard manual and there's no 55 in the BIOS post code list. I get a code 22 for a few seconds when I have no RAM installed and then it also goes to 55 I'm coming to the conclusion that DIMM slot 1 and 2 might be bad on this motherboard. Does anyone else have experience with this particular motherboard?
Thanks again. I'll try to check it again tomorrow. I've already removed the CPU twice and checked from every angle to see if any pins looked different, and they all look fine. I'll try to check it more closely tomorrow I guess.
Usually, if one or more slots do not work, it's a bent pins issue (assuming the RAM modules are properly installed and there's no short motherboard-chassis).
Try reinstalling the CPU and check the CPU socket for bent pins (use a magnifying glass or take a high res picture).