Pulling my hair out so any help is appreciative -- I have an asrock Z77 extreme 4 motherboard, prior to being an idiot and testing things... 4 memory slots were working using Crucial Ballistix Sport 4gb RAM.
I was helping test memory for someone (DDR3 so not an issue with this MOBO) and took out all of the current RAM and put in his RAM, also Crucial 4GB but not Ballistix Sport they were 1333. I immediately got an error message so I took out the RAM and put in the ones I had.
Following this, I received error message 55 (4 beeps) and failed to POST. SO now my RAM does not work!
I tested each individual one in each individual slot, (all of them POST and all of them worked). I also took out 1 of the Crucial Ballistix 4gb RAM and it works with 3. I put 1 in, it does not work. It does not matter what position it is, I thought it might be the board itself but everytime I either have 2 or 3 they all work no matter what slot the RAM is in... When I put all 4 in, it fails error code 55...
I don't understand what's going on here so if anyone has any suggestions please let me know... Really confusing as all RAM works individually and all slots work just not all 4 at the same time!! ERGH!