I purchased a used Roland SC-545EX. I soaked the heads and used the syringe to push & pull cleaning solution several times increasing pressure over a week. Finally I was able to get the printheads clean. Enough to do the waterfall when a lot of pressure was applied to the syringe ensuring the circuit board did not get wet. After drying I was still was unable to print... not a drop. None of the printheads will put out any ink. I replaced the filters and the black plastic thing that the filters go on, pulling ink in each dampener. Also replaced a few flat cables and verified the caping station & pumps worked. Where do I go from here? The fuses are fine, and I’m getting voltage on both the main board and the print board. How do I troubleshoot if its all six printheads are bad (I feel it is unlikely) or a circuit card? Is there a definitive test for heads or circuit cards? I figured I would check here before I put the print heads in the sonic cleaner as a last resort. Do I need to be hooked up to a PC for test prints to work? I’m waiting for a new power supply for the pc that came with it? I even tried to test one head at a time in maintenance mode. No failed tests either: Any suggestions would be greatly appreciated!