what caused this?

my computer ram or mb is damaged.. i had to remove ram to get it to start up, then it shuts itself off. so looks like 2 bits of ram died or mb fried??

iam getting a new mb and new ram, is it safe just to rig it all up? what could have caused this problem? my psu isnt in the best condition.. could it be that? (the comp wouldnt start until u took ram out, pressed power, switched off, re-instered ram - then it would start up - then switch itself off again and wouldnt start until u took out, re-inserted ram again)

any thoughts? thanks