The TV is brand new - I bought it in November. (Not refurbished)
My boyfriend is a day trader and uses the TV with his PC as a second monitor. The TV never turns off and on unexpectedly while it is being used with the PC, even when we use it as a screen to play movies on through Media Player on the PC. It also does not happen when we use the TV with the DVD player.
The TV is hooked up to a cable box from TimeWarner cable. The audio is a Yamaha RXV2400 receiver. Video is fed through an HDMI cable which we bought new with the TV.
There are basically 3 things that happens with the TV when we're watching cable and DVR'd programs through the cable box:
1) TV randomly turns itself off and on every few seconds to every couple minutes (not related to the remote - which is sitting out on the coffee table untouched). When I say it turns off and on, I mean it appears to be rebooting itselt. The TV plays a little jingle when being turned on or off during normal use. It makes this sound when the issue occurs as well - like it's rebooting. The sound of the program we are watching continues to play normally without interruption when the TV has the problem. When the TV comes back on after about 8 seconds, the picture picks up at the correct spot to match the sound, which had continued normally. The TV turning off and on occurs the most frequently of the four errors we get.
2) The screen freezes with blurred image. The screen will freeze and the image will turn into vertical lines of color that extend over the whole screen from top to bottom. The sound also continues to play normally. This occurs sometimes a few seconds after a successful reboot after error #1 as described above. We turn the TV off and then on again to resolve this issue.
3) Picture freezes. The picture will freeze an image and not move. The sound continues to play normally. This occurs least often. We turn the TV off and then on again to resolve this issue.
4) Rarely, the TV will display a message that says "searching for signal". We turn the TV off and then on again to resolve this issue.
There appears to already be an issue with our cable box. The s-video and component cables cause a series of lines to migrate up the TV from bottom to top. They move slowly and are kind of grayish lines are most visible against a dark or black background.
We have called the cable company and they have rebooted the cable box. This didn't work so we called them again and they boosted the signal (we live in NYC). This did not have any effect on stopping the 4 issues described above. The cable company then sent a technician to our house but he was unable to resolve the issue (he pointed out the issue with the cable box - s-video and component issue causing the grey lines described above).
He was supposed to return the following day with a new cable box to see if that was the issue, but never returned. We called the cable company who said the guy had marked our case as "complete". We opened up a new request for a service call but don't have a date yet. In the mean time, we cannot watch TV for fear that all this rebooting is causing damage to our TV (which is critical for my boyfriend's day trading business).