Please check connections to 1HP board.
From your picture, it appears you have not connected them in the correct place (looks like it to me).
Only you can confirm this by removing them and the 1HP board.
Look at the 1HP board and you will see the header legends printed on the board.
The correct harnesses must go to the correct header legends on the board.
This is the only board, where you can accidently connect the harnesses incorrectly as there is no polarisation on CN1/CN2 and CN3/CN4 connectors.
If I recall correctly:
If CN1 and CN2 are swapped over, the AVR will not start.
If CN3 and CN4 are swapped over, you will have a dead MFP.