Hope someone can enlighten us a bit. CS-5050 pops a C-6400 code. Replaced the Power Supply, no change, replaced Engine PCB, got a message that eprom does not match serial number, switched eproms and the C-6400 came back. Any help appreciated.

i think you have to put back the original power supply and engine pcb to fix the problem with the serial number, then run sim U163 "fix fuser problem" to reset the C6400 error

Tbanks for the reply Mad. My tech had just found the notes on C-6400 error, the service manual doesnt lead you in the right direction.

What the hell is Tbanks?? LOL....I meant THANKS