C6400 error on KM1500

[Crown Delorean]

C6400 zero crossing signal error.

Accordingg to the service manual, I have repalced the YC7 connector, and the power supply board. Still failing.

After a few experiments, I realized what the memory on the engine board (24L032) is burned.

I switched the engine boards from two machines, C0180 error, the machine number is stored in flash memory at the engine board, then i switch memory betwen cards, same as start, C6400 is shown.

An engine board from another machine is automatically rejected, showing a C0180 error (machine number mismatch)

Does anybody has a memory image from a new engine board?

Can I change the machine number from a memory image from another machine?

[dwparker.wa]

Before you swap anything else, reset the fuser code with sim.163.
A zero cross error is usually caused by the wall power being bad, not the copier.
Parker

[Crown Delorean]

Thanks, but i can't get into service mode, How can i do it?

I've tried as is in the manual, but it doesn't work.

[kyoceradude]

Leave the front door open then plug it in, turn it on. You should be able to enter service mode.