Roland XR-640 B head not printing

[Mr.Bundy]

I have a XR-640 replaced A & B Head Replaced head cables . Print head board replaced . Keeps Blowing F2 & F3 fuse. Just A head Is printing . What Could I try next . Could it be the Long 6 cables going from Print head board to Carriage board .

I am running Out thoughts . I can't see what the F2 & F3 fuse goes to

 

[netsol]

what caused you to replace the 2 heads in the first place?

 

[Mr.Bundy]

what caused you to replace the 2 heads in the first place?

Just came into work and printer was telling me Temp to high 114 and was beeping . Head A was due to be changed was in service for 6Years and had Alot of clog nozzles . Since Head A was printing I fig it was in Print head B. So I went head and changed both heads and Head cables .

 

[netsol]

That answers my question. (What happened first?)

REALLY CAREFULLY unplug head cables & be sure 1 foil isn’t folded over.
isn’t there 1 cable on this machine that is different? (It has 1 foil More or less than the other?)
it is possible one of the large transistors that power the heads has shorted out

one more thing, is one cable flipped? (Inserted wrong side up?)

and one more thing, when changing the heads &cables, did you UNPLUG AC POWER & wait 15 minutes before changing parts? (Sounds like a folded over foil on ribbon cable or shorted power transistor)