My TV turns itself off, usually after about an hour or so. Sometimes it hiccups, makes a crack noise and blips but continues. Now it doesn't turn back on. I plugged in another TV. It hiccupped! So I changed Cable boxes from another room. I don't want to ruin another TV so I thought I would ask.. Could it be the cable box or the electrical plug? The plug has been fine for years.

Hello zyx52072

Sounds like a hardware problem either in the power supply or in the (horizontal) deflection section. If it is a tube type television, is there also a slight strange smell involved near the unit? (That would indicate a possible high voltage discharge).
This type of repair requires a trained technician.

:>)

Thanks for your answer. Since this TV is 15 years old, it is going to Goodwill to be recycled. Thanks again.