chr1s

I've got a CV that's now displaying "scrambled" graphics at startup, after having powered up just fine just a week ago. The CV is fully functional with a 2600 adapter, so it seems these DRAMs could be the culprit? All three p/s voltages are getting to the main board, and I've disassembled, cleaned and lubricated the on/off switch. How could I go about identifying a faulty DRAM?