Having problems with a 50h81. Unit will not power up and I'm getting a clicking (5-6 times/sec) from the front left of the board and a matching tapping sound from the speakers. Sounds like a safety cutoff, but I'm a novice so I'm not sure. Any suggestions to get it to work? BTW, Got the TV from a lady who didn't want to get it repaired after she said the "speakers quit working". I use a sound system 100% of the time so speakers are of no use to me. Hoping to get the unit running and any help would be great. Thanks in advance --P81