Need some help troubleshooting m/b issues


Platinum Member
Aug 7, 2003

recently I've been having some issues, losing my SLI config sometimes after a reboot. One or two times my rig closed in games, and immediately I thought of my trusty but old (7yrs) PSU. I went on and continued using the rig until one day the second PCI-ex16 second lane wasn't usable anymore and after one or two times PC wouldn't even boot anymore. I thought my PSU died on me and all the facts led to that.
So I purchased a SF Platinum 1Kw yesterday. After I installed it, PC wouldn't boot. After some plugging/unplugging I found out that the first two memory lanes are probably damaged. I use 4 sticks of 4Gb and after using all the possible combos, I concluded that the first channel (first two memory lanes closest to CPU) wouldn't work.Only when I removed them PC booted just fine and recognized everything. (shock #1)
So I boot SLI is enabled I play for a bit, everything else works fine and after a restart, again issues with the second PCI-e x16 lane, so no SLI.. From that time no matter how much I tried I cannot make the second PCI-e x16 lane to work. Both GPUs work fine on the first PCI-e x16 lane and none of them works alone on the second one. Which leads me to believe that the second one is damaged somehow.
Now my main problem is to clarify if this is due to a faulty PCH on the mobo or is it a problem with the CPU, since as I said the first memory channel does not work anymore as well.
On the GPU-z tab the first PCI-e x16 lane is recognized as 8x, which is not a good sign, it should be x16 and coming from the CPU right?
On the BIOS in the PCH configuration the first PCI-e slot says also 8x and the second PCI-e slot says "not detected" .
So what I'd like from you, is some ideas about how to troubleshoot this correctly and find out if it's a CPU or mobo issue. Probably PSU damaged something when it was dying and I'd like to know what in particular. I don't want to buy a new s1155 mobo only to find out that it's a CPU issue. Unfortunately I don't have a second mobo/CPU to test so this is out of question.
Any help to resolve this would be greatly appreciated, thanks in advance :)