tomlee59 saith sooth. The logic-board-to-display cable is stiff, as you know, and has to be 'crinkled' to allow the case halves to be separated for connection/disconnection of the cable while yet being able to compress out of the way when the halves are re-assembled. Its ageing plastic and the wires together make it stiff and give it a spring-like 'memory' of its usual functioning shape, which can be enough to pull it from its mating upper connector even as the PB is reassembled, especially if you have given it an extra 'crinkle' during your handling of it. This alone could be responsible for the display horrors, and is part of the reason for ensuring the integrity of all internal connectors.

If you have had the inverter board out, it needs special care to ensure, at reassembly, that the slider buttons for brightness and contrast are mating correctly with the linear control potentiometers on the inverter board. Check also that some wag has not replaced the blue 350VAC inverter board for a passive FSTN display with a green 400VAC board for an active TFT display (from a PB 180). The correct boards are 922-0025 (160) and 922-0024 (180), which are easily confused if one is colour-blind. Another possibility is a mismatched display from a PB 180, swapped in without consideration of the higher inverter voltage needed for the TFT display. Does your display exhibit the 'submarining' characteristic of an FSTN display when you move the pointer?

de