Whenever a television starts doing this the motherboard/main board and or power supply is usually at fault. The power supply can usually be rebuilt for around $150 depending upon the knowledge and skill of your local television repair shop. To replace the parts is usally more expensive then it would be to purchase another television ($300 and up). For troubleshooting you can unplug it overnight to try and power cycle it but it sounds like your problem is beyond doing any type of power cycle to get the television back going again. It would need the repair shop or to be discarded for another.
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Whenever a television starts doing this the motherboard/main board and or power supply is usually at fault. The power supply can usually be rebuilt for around $150 depending upon the knowledge and skill of your local television repair shop. To replace the parts is usally more expensive then it would be to purchase another television ($300 and up). For troubleshooting you can unplug it overnight to try and power cycle it but it sounds like your problem is beyond doing any type of power cycle to get the television back going again. It would need the repair shop or to be discarded for another.