Not entirely. it isnt easy at all, and its very painstaking swapping one chip out at a time.
However....
Sometimes the traces get broken going to the RAM ICs, so i would grab a magnifier and check all the connections going to the RAM. I will dig up the schematics and post the sheet on the RAM section which may help.
if an IC itself is bad, only fix is to swap them one at a time until you find them, or replace them all.... it sucks. Been there, done that.