After I removed the blue and black printhead, it is no longer working. I may or may not have unplug the power cord. I remember doing it, but not sure now. Some say it may be a fuse or capacitor problem. When I swapped the ribbon cable with the yellow and magenta, the black and blue printhead worked but caused the yellow and magenta printhead not to work. So I know it is not a printhead issue and must be the board or fuse. I found 3 fuses that is visible, 2 on one board and 1 on another. Fuses seem good. Can you please advise?