My Hitachi 42PD8700U Plasma TV has developed a fault.
Set up: Rooftop aerial to blu ray player to TV, Blu ray also feeds Philips sound bar thro' an optical cable and an HDMI gold plated cable feed to the TV. Viewing as interrupted by the screen changing to small multi coloured squares which formed columns and lines on the screen.
Switched everything off. Switched back on after a 20 minute wait. Blue screen with 'No Signal' showing. Set Blu ray back to factory settings.
This resulted in no picture at all so could not reset my settings, Disconnected all cables from the TV and switched on. No picture or blue screen. dark screen with two vertical lines down screen. One a little to left of centre the other just to left of right edge. Switched off and left totally disconnected for 24 hours. Plugged TV in to power up and achieved a blue screen. Switched off and reconnected all cables within the set up. Success, good picture and good audio for a couple of hours. No signal again. Waited and all returned to normal. A further few hours of viewing resulted in total failure, no picture but good audio. TV currently standing isolated and rejected. Smaller TV in use to replace the plasma and this set up is working fine. The plasma is about 6 years old I think!