SP-540V blowns mainboard fuse constantly

[Robert72]

Hi there, I'm new to the forum and I've seen very skilled people here.

I have a Versacamm SP-540V with a weird problem.

It blowns the fuse of the Black-Cyan head. I thought it was due to a short-circuit in the printhead, as I cleaned it with a syringe, but with the new mainboard it has the same behaviour.

I've tried to swap the printheads ribbon cables and then it prints black and cyan, so the printhead is ok. I've tested all the pins of the ribbon which comes from the mainboard to the printhead controller and all is ok.

So if it's not the mainboard and it's not the printhead, what thing could be? can have the ribbon a short-circuit? I tested continuity between pins but not for short-circuit.

Could the printhead controller be damaged? (the small board over the printheads)

Please if you've encountered any similar problem, please let me know, as I don't know how to continue.

Thanks and best regards,
Robert.

 

[tdgraphics]

Just a thought, each print head has a specific voltage and this needs to be set in Service Mode when you change the head. If you don't set the voltage, you can damage the head.

 

[Robert72]

No, there's no problem regarding the head rank. The first thing I did is start in maintenance mode and inserting the head rank id.

Tomorrow I'll try a new carriage board. It's the only thing I've still not tested.

I'll let you know if it's fried.

Thanks and berst regards,
Robert.

 

[Kev41]

Sounds like a ribbon cable, they sometimes wear on the running tray causing them to short.

Kev

 

[Robert72]

Hi Kevin,

are you referring to the ribbon cables which comes from the mainboard to the carriage board?

I reviewed continuity it those cables, but I didn't check for short between pins.

The other ribbons (the smaller ones which comes from carriage board to the printead) are brand new.

 

[Robert72]

Solved!! The (used) mainboard I got had a problem due to an electrical surge.

I swapped to my old mainboard, soldered a couple of radio car fuses and I'm up and running again.

Remember this, when you have a damaged mainboard due to a shortcircuit in the printheads, the first thing is to be sure that the shortcircuit is gone, and then test the mainboard fuses. You could repair it with new fuses, spending only a few bucks, and saving thousands.

Regards,
Robert.

 

[iprintstl]

so what was the short?

 

[Robert72]

The short was in one printhead which suffered some water spill. Even when I dried the printhead it also remained making short-circuit. That's what confused me. I thought the printhead was ok when dried, so, when it was wet it damaged the mainboard. But not, I put a new printhead and the radio car fuses on the old mainboard and, from that day, the machine prints flawless.

I love those predictable Roland machines. Only if they could be faster!!!

 

[Scott Greenslade]

Hey Robert, I beleive my sp 300v has blown the fuse for the black cyan head. How did you go about replacing he fuse? Do you have any diagrams that you worked from and what are the specs on the fuse?
Thanks Scott

 

[Robert72]

Dear Scott, tomorrow I'll try to post one photo of the location of the Fuses. You only have to disconnect your machine from current supply, open the back cover and test continuity with a polymeter.