No power and no sound

When I turn on the TV I get no picture or sound. I replaced the AU board 3 times with the same results. All 3 boards have the same p\n as the original board. What else could be wrong with the TV.

crwdns2934089:0crwdne2934089:0 crwdns2934093:0crwdne2934093:0

crwdns2934109:0crwdne2934109:0

crwdns2889612:0crwdne2889612:0 0
crwdns2934285:0crwdne2934285:0