Hi @merbilefern.   Presume you've checked through these troubleshooting steps:   • Ensure the Sleep Timer is set to Off in the Setup menu. • If your PC is connected to the TV, check your PC power settings. • Make sure the AC power cord is plugged in securely to the wall outlet and the TV. • When watching TV from an antenna or cable connection, the TV will turn off after 10 - 15 minutes if there is no signal. (Related to that there may be a timer on a set-top box causing this too.)   Unsure if a software update would help as beyond the stuff outlined above, TV power issues have a tendency to be more hardware related. However, to see if a software update could help you out here, what's the current software version on your TV?   Edit: Latest software version available to download from the Support page here is  T-TDT5DEUC-1024.1. ... View more