LED flashes 4 times
SOURCE: i get a red screen
In most cases on these models the red crt is shorted and causes the set to go into a shutdown mode and flash the timer light 7 times. The part number for the red crt is 8-733-664-25 but is no longer available.
This sounds like a power supply issue. TVs operate on DC current and therefore must have a power supply board to invert AC house current to DC as well as regulate the DC current supplied. Heat is created by this process and therefore certain components on power supply boards are prone to failure due to repeated overheating. I would suspect capacitors on the power supply board are failing so they are only able to store enough power to allow the video board to work every 30 seconds and then it shuts off again. You can replace the whole board but I have repaired these before for a few dollars and some soldering.
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