MP 780 will not power up

[on30trainman]

BTW, what's your take on the "missing" readings on four of the terminals ?

I sure wish that dang service manual listed the outputs !

My guess - ground pins or open/unused pins

 

[Trigger 37]

jflan,... the last post is the answer. The other pins in the cable are for ground. There is a separate ground for the logic voltage, another one for the drive motor voltage, and another one for the printhead voltage. They all look fine to me. The problem does not seem to be with the power supply, or you would not have any voltage at all. The problem is with the control circuit that turns the printer on. Like I said before you need to take the unit apart and start checking the wiring from the power on switch down to the main logic board. I have been through the manual and there are no wiring diagrams shown and no pin assignments for any connectors. Canon must have much more detailed repair manuals that they provide Certified Technical support service people, but those are not available to common people.

 

[jflan]

Thanks for all the assistance...
I'll keep pushing on when I have time.

There's steelhead in the M.F. Willamette R. that I need to tangle with