Asrock RAM Issues

Hello,
I had a ram issue which I spent all yesterday finding out the problem and cause.

What happens if I put the bigger DDR3 RAM in all slots will detect it but once I put the smaller ddr3 ram in which is same speed and different brand though it wont be recognized in the last two ports.

Im stumped could it be the motherboard? I don't see that since all slots seem to work But anything is possible. Or could the ram be on its way out which in that case I buy another one of my bigger rm (Apacer) to replace it.

Motherboard: Asrock FM288x-extreme 4+

Thanks!

For a few days thought it could of been the board the slots work by testing it.

Maybe I should buy a 2 dual channel kits and use that in the board.

Right now I'm running on 2gb to be on safe side putting the other ram in the top port might do damage who knows.

This I the model and its not on the list Kingston kvr133ds8n9 might be why then so be better of getting a ram kit. I use my 2gb stick for now.

Thinking about selling my small stick first but no one seems to buy them on eBay.

For some reason when I put the smaller ram on the top slot and the bigger one in the third slot it would only detect the smaller ram...
I took the smaller ram out now the bigger one I not being detected just a black screen :/ weird

Tried to put each in a2 and b2 only the small one is being detected in port2 but now not in other ports and the bigger stick does not work in any ports now. It always starts happening when I put the small ram stick in

I tested the sticks by them selfs and together

Maybe its time to RMA or get a new board with a tight budget and go back to using my slow un gaming 1995 system

what I find funny is never had. Problem using the 1 stick now the probable returns.

just my luck..

Thanks for all your help so far

Any ideas what to do now...