Roland Sp540 no ink printing

[printcore]

Hey Fam. I have a Roland SP540i replaced encoder strip, sensor, cairaiage bearings to solve error code, this solved my problem but, now there is no ink on print or test print at all, prior to repair it was printing fine, ink pulls through capping on cleaning very clearly, Bothe 1.5A glass fuses are tested and not blown. My question is if a Transistor is broken wont the glass fuse also be blown or could the transistor be broken with good fuses still in place?

 

[damonCA21]

Have you tested the head fuses on the mainboard ? These are small surface mounted ones, and are the ones that control the heads. It is possible transistors can be damaged without blowing the fuses, but is unusual for it to happen.

 

[damonCA21]

Can you post a pic of the fuses you checked so we can see if they are the correct ones you are looking at?

 

[damonCA21]

Also, when you did the work on the printer, did you unplug it from the wall and leave at least 15 minutes before doing it as if there is power in the board still and you remove or dislodge the head cables, this can blow the fuses or transistors. It is odd that nothing would print though as that would mean all the transistors had failed, normally it will just be one or two, and a couple of colours drop out and the others work ok

 

[printcore]

ok so the F2 fuse tested blown, but i can only find a 5A replacement locally, putting the 5A in gives me a Scan Motor error, when completely removing the fuse i get no error code.
Then testing the transistors i now found 1x reading 0, annd the other 3 are variants in the range of 4.3 ish.
The 1.5 A glass fuses are good.

 

[damonCA21]

Don't put a 5A fuse in there or run it without a fuse as you can end up ruining your board ! The glass fuses are just for the main printer power, they don't have anything to do with the heads. F2 is the one that is for the head. It looks like you have blown one of the transistors when the head blew so that needs replacing. This is why the printer is not printing.

 

[balstestrat]

Whatsapp pictures.... useless. Sometimes it's something so tiny you might only spot it with microscope.

 

[damonCA21]

Whatsapp pictures.... useless. Sometimes it's something so tiny you might only spot it with microscope.

I think it is more likely the transistor has blown given the other problems the OP had. A bad joint on them is pretty rare

 

[netsol]

MOST TIMES a conductor on a ribbon cable fold over causing a short

 

[netsol]

betting on a bad transistor

 

[printcore]

betting on a bad transistor

Was transistors indeed, did replace them and printed fine for a minute, then noticed damper leaking on manifold, replaced these run test print and all good but ZERO BLACK, set new cables still no black, any ideas

 

[printcore]

I think it is more likely the transistor has blown given the other problems the OP had. A bad joint on them is pretty rare

Was transistors indeed, did replace them and printed fine for a minute, then noticed damper leaking on manifold, replaced these run test print and all good but ZERO BLACK, set new cables still no black, any ideas

 

[netsol]

do a couple hour headsoak on the black
pull ink through (don't be afraid to throw a little ink away)
then try printing black again.
black has a lot of solids in the ink

 

[netsol]

also, check your soldering, recheck the driver transistors (they dont go bad often, but, they do go bad....)
CAREFULLY CHECK the transistors driving the black print head the collector of one of the complimentary pair should have 41 VDC (center pin of the transistor)
the collector of the other transistor should be grounded
did you check/change the ribbon cable?