@rekeren Sounds like a connection issue. After unplugging from wall outlet open up the touch panel and digital display and locate any connection points to the display, unplug them and dip a cue tip or micro fiber cloth in rubbing alcohol and wipe off copper connectors as best as you can. Make sure the contacts are air dried before you plug them back in and that should resolve the issue. If not check for damage to connectors in the touch panel. It could be from age (dust/humidity over time) or power surge. Hope this helps!
- Jacob