I don't know what exact model you got but if you read like at Wal-Mart reviews that seems to be a main complaint on these
I got this one for all the good pc monitor reviews and so far in 6 months its has not disappointed , but I also grabbed the extra Wal-Mart warrantee with it for whats been said like for you and seen that the folks that had it[extra warrantee] and then issues with the set got the best satisfaction for a return or repaired over the ones that did not ..
Honestly, the power board probably went, or mainboard. unless you are good as soldering and have an ESR detector to find out if any caps are bad and you can replace them, it's probably toast and the coast to get a new board or PSU is probably the cost of a new 32" TV. The things are so cheap now, it's not worth repairing.