When switched on the television picture drains colour from the edges and then 'implodes' in on itself in about a second. Then it turns itself off and a couple of seconds turns itself on again. It then continually repeats this cycle. Picture>draining edges>implosion>turns off and then turns on again; until the set is completely turned off.
Its a Sony KV-29F1U and is about twelve years old. Grateful for any advice please.