Tcl TV turns off while watching on its own - TCL 50 Class LED HDTV - 1080p, 1920 x 1080, 16:9, 60Hz, Clear Motion Index 120, 5000000:1 Dynamic, 8ms, 3x HDMI, VGA, Energy Star LE50FHDE3010 - LE50FHDE3010

Question edited for clarity 'make model (what it is)'.

How to Fix TCL Smart TV Remote - Support.com TechSolutions

https://www.techsolutions.support.com > how-to > how-...
Learn to solve common troubles you may have with your standard infrared and enhanced TCL Smart TV Remote.

TCL Roku TV: Wifi Internet Not Connecting? Try this First!!

https://www.youtube.com > watch
PREVIEW
2:47 I show you how to fix a TCL Roku TV (smart TV) where its not connecting to the wifi internet network (No Connection). By the end of this ...
YouTube · WorldofTech · Sept 16, 2020
Missing: 65R625 ‎' Must include: 65R625

TCL TV WiFi Not Working (Disconnects/Won't Detect/Connect)

https://readytodiy.com > tcl-tv-wifi-not-working-discon...
If your TCL TV WiFi won't turn on, press the 'Home' button on your remote control > press the right arrow button and select 'Network' > press the right arrow ...
Missing: 65R625 ‎' Must include: 65R625

Led strips need to be repaired or replaced ,

https://www.youtube.com/watch?v=KaKi5aC9fUQ

Do a factory reset

https://tclreviews.com/my-tcl-television-wont-power-on-how-to-fix-it-in-6-easy-steps/?cn-reloaded=1
https://www.google.com/search?hl=en&sxsrf=ALeKk02jj6tWIMBCOV8sp68OydNJ3hCEdg%3A1586736353799&ei=4ayTXoekMMTUtQXi4ZHIAQ&q=tcl+l32b2500a+will+not+turn+on&oq=tcl+l32b2500a+will&gs_lcp=CgZwc3ktYWIQARgAMgUIIRCgATIFCCEQoAE6BAgAEEc6BQghEKsCSg4IFxIKMTAtMTI3ZzE0N0oKCBgSBjEwLTNnNFDawQFYrucBYNaHAmgAcAJ4AIABvAKIAcUGkgEHMC40LjAuMZgBAKABAaoBB2d3cy13aXo&sclient=psy-ab#kpvalbx=_BK2TXrrvLcuGsQWavKe4Dw39

https://www.youtube.com/watch?v=WTmJb2Sl-vI
https://www.youtube.com/watch?v=QKbZGYNXkI8

You can use the RCA style jacks, Yellow for video White for left and red for right audio OUT . Connect the TV end the same way. Note the source input number on the connectors of the TV. Turn both the TV and the Sony on. On the TV, select the input number the cables are connected to and you will see the Sony . If there are no unused places on the TV to connect to then take off the antenna/ cable wire off the TV and put it on the ANT IN connector of the Sony. Obtain a jumper cable wire long enough to reach the TV from the Sony and select either channel 3 or 4 whichever channel is not used in your area on the back of the Sony. Now turn both on and select TV as the source and put it on channel 3 or 4. Now turn off the Sony and change the channel on the TV to any other one in your area. If there is no picture, then the Sony will have to be on while watching TV.

Unplug the tv and hold the on/off switch on the tv (not remote) for 30 seconds. This should clear any power left in your electronic boards. Then plug it back in and try again.

try the 'default' setting of the tv.
menu-setting-restore default.