I home-built a system in January and started having all kinds of problems with it in June. BSODs all the time - when gaming, when not gaming, while the computer was trying to run Startup Repair, while the computer was running system restore, etc. All the problems pointed to a RAM issue, but I've tested my RAM extensively and tried running 3 different sticks individually - doesn't help. Then I thought it might be a software issue, so I tried reformatting my hard drive several times - didn't help.
Then my computer froze while I was editing the BIOS. I immediately thought "must have been a bad MOBO the whole time" and RMA'd my MOBO. Got it back, plugged it back in, and got freezes on my first attempt to start up.
At this point, I decided I was going to RMA my hard drive, since the error I get when trying to run startup repair is an ntfs.sys error and the hard drive is the last "key" system component that I haven't RMA'd. But, while I was in the middle of this, my system froze a few times during the MOBO's startup splash screen.
I'm pretty ignorant when it comes to computer, but I was under the impression that the computer hasn't even begun to access any components other than the MOBO at this point in startup, so any issues here would likely be related to the MOBO. That said, I just RMA'd the MOBO.
So what should I do at this point? Continue with the hard drive RMA? Send the MOBO back and complain bitterly?