Motherboard came to an end? can't see oz?

Question

ASUS

Hello everyone, until today everything was fine, there were 3 bars of 2GB each, at lunch everything hung up and 2GB out of 6 became available, changed the bars in places again it became 6 and everything seems to be ok. after a few hours the PC freezes, after rebooting the black screen (the coolers worked) again changed the memory in places and again it became available then 2 then 4 GB ... what could be the problem ??? if you leave 2 dice, then everything works, and any. The dram led
upd is also on on the motherboard, after a few hours there were several reboots and now the PC does not turn on at all (the coolers work but the screen is black) changing the RAM does not help, the PC refuses to see it
P.s p7p55d-e board for about 8 years