A computer with two RAMs does not work

Recently I started the computer and the error "boot block compatible ver.013 cheking for cd room" appeared, removed one RAM, and it all worked, inserted another second, the monitor stopped working, removed it again and works again, I can not figure out what is wrong? Maybe the motherboard does not have time to pull the 2nd operatives for 2GB? (motherboard Asus m2n68-am se2)