If this is a crt type projection television, it is usually due to sealant breaking down on a coil or transformer allowing the coil to vibrate at operating frequencies. Replacement of an individual noisy coil or transformer on the printed circuit boards would probably be repaired at a reasonable cost. Should only be expensive if its a crt 'scan coil' vibrating, which are difficult to re-seal and could require tube replacement. (Scan coil vibration sounds rather hash and is of a low pitch).
Cobweb, September 2004
