Hello, I can help, I had this problem on my Firepower II, You must reheat the two main boards (where the batteries go) (and where are the coil transistors, lights, etc) if that doesn't help, try also the display board.
Another problem that I see is a bad contact on the display, that is fixed with a connection jump, but it is better that first you try to reheat the cards of all the pins and then verify What happens next