Hi sir:
Which error code do you have ??
Normally, you must to do the following Steps: take up all electronic boards: clean it the edge connector, from corrosion, dust or similar, and clean with eraser pensil, and then spray with contact cleaner.
2) Retighten all connector, wires, see if are NOT broken, or open or loose,
3) clean all sensor around the machine, and tight very well his repespective connectors,