roland xc 540 can't get A to print

[jackrowe2010]

Hello need a little help here. When I do my test prints I don't get anything out of A I have switched the cables from B to A and the colors come out so it is not the head I replaced the cables for A and still nothing I even got the print head board worked on which needed a new transistor and a couple of fuses does anyone know where the problem could be I am thinking a cable problem internally

 

[FrankW]

The Fuses for the heads arent on the board on the carriage, they are on the head board below the black cover at the rear of the printer. I had such issues several times (I'm a technician), but NEVER had internal cable problems. Fortunately, the XC-fuses are not soldered, so you can change one to another to test.

 

[Papajo]

Most of the time if a fuse is blown on the head board this means you have a shortcut into one of the heads of the A group due to ink leakage on the circuits inside the head (often following a shock on one head or due to the usage of third party inks). You have to determine which head is the problem. If a transistor is blown it will tell you which one of the heads is dead. You have 6 rows of transistors on the board corresponding to the 6 heads. If the blown one is on the first row then head 1 is dead, if it's on the second...

If all the transistors are OK then you just replace the fuse and plug the heads of group A one by one and try until the fuse blows again (don't forget to isolate the flying head wires before pluging the machine on again).

Also if a transistor is blown there can be other components blown like chip resistors around the transistors. Most of the time it's a good idea to replace the head board given that you spotted the faulty head first.