Have had several cheapie LCDs where the panel has plastic backing (not metal). They become very erratic - blanking out, los of signal,
glitching etc. The fix was to lift the pcbs, cover the panel backside with al. foil and reassemble. Appears to work as I've done quite a few.
My unproved theory is that the panels emit a lot of garbage as they age and this trips up the eeprom. Bruce