My System stopped booting on 8gb,but will on 4

troubleshoot each stick individually, put in one stick and boot, run memtest86, if it passes try the next. if all 4 sticks check out, test each slot, usually by inserting them one by one until it does not boot. reply back to let us know how that goes.

I have 2 (A) slots they boot each individual stick boots up ok...The 2 (B) slots they are the prblem , no post no monitor....

are there any error beeps?

ah no no beeps at all..and the Monitor stays off

odd, have you tried both memory slots individually? usually when a slot goes bad all it does is not pick up the ram on the system. there could be a short somewhere, maybe some dust that's slightly conductive got in there. try some compressed air in there and let me know how that goes.

OK yea I will....I'll get back to you..

yea still no luck..for some reason I think its the board...but I am not sure.

sorry for the late response, can you see the RAM slots that are empty in the BIOS when you get it to boot?