My Sony KV-32HS420 Trinitron Wega TV will turn on but then shuts off again after 5 seconds, never showing a picture. The "Stand By/Timer" red light on front blinks 7 times, pauses, and then repeats. I've tried unplugging for several hours but the problem persists.

You have what is commonly known as a shutdown problem. It's an overload in one of the internal circuits. It needs to be looked at by a professional tv reapir person.

Pls. check the tv supply plagh is not proper canected or sperking with mains plagh pin so checked first if ok then problum is inside tv set this problum is output supply from EHT is blocked or discanect so pls. check output dyoide or 1 ohm registance is open or cancting spear. i think this is not expanciv