my box turning itself off/on went into EM was scrolling through and it went off no lights on the box switched it from the mains for 5mins switched it back on picture came and started to flick off and on in secs could it be the power supply going?
cheack connection between the input power cable block and board they have been known to break over time . might need resoldering , could be failing caps in which case use a little heat to track down the cap ... or replace a few at a time around the power circuit.