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)

 

[Mr.Bundy]

Yes I checked all the cables . just replace cables head cables
I double checked to make sure cables are in the right order
Yes I waited before I changed parts .
I just swapped out print head board. I checked all transistors. they checked out good .
after all that . Print head A prints a good tested print. Head B A yellow band the size of head over top of test print .
Then I print again. Then its faults after it prints like this . service call 0250

 

[netsol]

the yellow band going across means that head is bad, or the cable (or of course that board)
over the years 3 of my black heads have gone bad that way

IT'S ALWAYS POSSIBLE one of the capacitors is leaky, or one of the small transistors further back is bad.

if you actually removed the transistors to test, it is possible that one of the insulators is installed incorrectly

 

[Mr.Bundy]

I did not remove transistors to check. I have a brand new Print head board I can put in . I'm going to do that to see if it changes.
Thanks

 

[Mr.Bundy]

Now printer s flashing 1_2_3_4_5_6_7_8_. and C MY K Lc LM LK CL flashing back and forth and will not do anything