Troubleshooting help required

[Stagecraft]

I made the stupid mistake of powering down one of my printers without setting the periodic cleaning to on and then leaving on vacation for a month. Of course when I returned a couple of the heads were blocked. In the process of trying to bring the printer back to life I blew a mainboard fuse while swapping cables while the machine was still plugged in. I sent the board out for repair as the fuses were soldered in place. After diagnosing the board, the repair shop said I also needed a new transistor which they installed along with a new clip-in fuse block as is used on some newer Rolands.
So after reinstalling the board, the problem printhead that started all this is firing just fine but now the black doesn't work at all.
These are the steps I've taken thus far to try and narrow down the problem:
Clean all heads
Replace all dampers, caps and lines
Draw ink through heads with syringe
Test print - all good except black is not firing
Swap ribbon cables (connect yellow cables to black head) - now black fires but not yellow, which tells me heads are okay
Reconnect as normal - all heads fire except black
Full cable swap between cyan and black - cyan still fires, black does not, which tells me cables are okay
Open case, inspect connections to board - all good
Inspect fuses - all appear good but I do a complete swap with spare fuses just in case.
Test print - all still printing except black
...any suggestion?
FWIW I do have several emails in to the repair place (Macmedia) buI haven't heard back from them.

 

[netsol]

what machine?

what is the model?

I made the stupid mistake of powering down one of my printers without setting the periodic cleaning to on and then leaving on vacation for a month. Of course when I returned a couple of the heads were blocked. In the process of trying to bring the printer back to life I blew a mainboard fuse while swapping cables while the machine was still plugged in. I sent the board out for repair as the fuses were soldered in place. After diagnosing the board, the repair shop said I also needed a new transistor which they installed along with a new clip-in fuse block as is used on some newer Rolands.
So after reinstalling the board, the problem printhead that started all this is firing just fine but now the black doesn't work at all.
These are the steps I've taken thus far to try and narrow down the problem:
Clean all heads
Replace all dampers, caps and lines
Draw ink through heads with syringe
Test print - all good except black is not firing
Swap ribbon cables (connect yellow cables to black head) - now black fires but not yellow, which tells me heads are okay
Reconnect as normal - all heads fire except black
Full cable swap between cyan and black - cyan still fires, black does not, which tells me cables are okay
Open case, inspect connections to board - all good
Inspect fuses - all appear good but I do a complete swap with spare fuses just in case.
Test print - all still printing except black
...any suggestion?
FWIW I do have several emails in to the repair place (Macmedia) buI haven't heard back from them.

 

[Stagecraft]

Duh...I guess that info would help wouldn't it?
It's a Roland SolJet 2 Pro V SJ745-EX
- I should add that I just heard back from macmedia and he's suggesting I return the board to them although they will be shut down for the next ten days or so.

 

[netsol]

i hate to say this, but if mac media. will do a re-repair, you should let them. having 2 sets of hands working on that board could be a disaster. (leading to lots of finger pointing and possibly invalidating any warranty mac media might offer you.)

i am always glad to help troubleshoot, i have gotten quite a bit of useful info from signs 101 & like to contribute where i can, but once someone starts a repair you should let them proceed.

i'd hate to see us in a week loking to buy a new mainboard and feeling responsible. since they got the troublesome channel back, this seems to be a repair they are capable of.

 

[Stagecraft]

Thanks for the feedback; I was getting a bit concerned as I hadn't heard back from Kent at macmedia after sending several emails. He has since replied and yes, I'll be sending the board back for round two.