Need Help Roland SP 540i not printing After replacing the head

[spodo]

please help with this problem , when I give the test it doesn't print anything
replaced the heads
replaced the captops
replaced head wires on the carriage
the transistors are fine, the fuse is fine, 41 volts pass through ,
I will return the old print head which prints the same problem

what electrical problem could there be? can the print carriage board be bad?

 

[damonCA21]

Yes it could be a bad print carriage board. When you replaced the head, did you power the printer down, unplug from the wall and leave at least 15 mins? If not you could have shorted something.

 

[spodo]

I replaced the carriage board, the problem is the same,

 

[damonCA21]

I replaced the carriage board, the problem is the same,

If everything else is ok then it sounds like your main board has failed. I do have a used and tested one in stock if you need it