During a repair to replace the OLED display screen on an Electro 6D, when reconnecting the ribbon cable (22410), it was accidentally inserted in the wrong direction into the socket clip holder. This is the ribbon cable that connects the circuit board for the control panel in the top which houses the display to the circuit board in the base (to the NE6 Main v 1.02 DM11446 board). The pins in the connector are all uniform, so apart from the little notch, it is easy to insert it the wrong way if not careful. It had to be disconnected to do the repair. When the keyboard was powered up, a light came on briefly on the circuit board in the base and then went off. The board was powered off, the ribbon cable direction corrected, but now after corrected, the keyboard will not power up at all. The main fuse appears to be ok (visually).
Where could the problem be? Everything is connected firmly but no lights come on anywhere. Is there another fuse to check or does something else have to be replaced?