Hp laserjet 3055 scanner error 5 turn off then turn on

Fat bed lid should be clean and closed, Scanner assy should move and scanner bulb should glow for a while, during the booting process.
The Flexible Flat Cable (pitch 1 mm x 30 Pin) should not be damaged (replace if damaged) and well pushed inside its jack in the formatter. (Open the right side cover and check).
The flat bed scanner's glass frame & Door base should mate perfectly with ease. If opened earlier, the ADF wire harness which passes on the inside along the rear right corner, can prevent PERFECT mating (if in palce the mating would not need any pressure and would fit in place easily), A gap of less tahn 1 mm can be the culprit.
If problem still persists open the scanner flat bed cover, clean the guide rod, check the laser assy movement, clean the black stripe above the resting place of the laser unit, laser unit mirrors ( 4 nos - with lint free fabric and Iso=Propyal Alcohol) re-assemble the flat bed cover with laser assy mid way on its path (to check movement when you boot). Ensure perfect mating as above stated.
If problem persists I fear you may have to replace the scanner assy or the formatter. Before you decide to replace formatter try "Permanent Storage Init" process posted by me for PC scanner "No connection" error.

GOOD LUCK