[Jeffhs]

I don't know much about flat screen TVs, but here are a few tips I found while browsing the support community website for Insignia, the house brand for TVs sold by Best Buy.

A buzzing sound from the power supply area, especially near the power transformer, is almost certainly indicative of an overload somewhere in the set. In fact, in the days of tube-type TVs, this was an unmistakable symptom of power supply overload; if it is left unchecked in either type of TV, however, it could severely damage the set.

If your TV is still under warranty, I'd return it to the store from which you purchased it for exchange or repair. If not, and the set is more than a year or two old, I'd junk it and get a new one. Flat screen TVs, particularly those with screens 19 inches or smaller, are often not worth repairing when they develop problems as the cost of repairs, including the often hefty diagnostics charges made by most TV repair shops, at least those that will repair flat screens, could and often do exceed the price of a brand-new set.

If the backlight capacitors are even slightly discolored, they could be going bad and should be replaced. Capacitors that are obviously bulging, at the top or elsewhere, are definitely defective and must be replaced immediately.