My TV light is on but the TV isn't getting on

It sounds like the TV is dropping into standby instead of fully starting. I’d separate the remote from a TV power/startup problem first:

1. Unplug the TV from the wall for 2 minutes. While it is unplugged, hold the physical power button on the TV for about 15 seconds, then plug it back in and try the TV button only.

2. Remove the batteries from the remote and try the physical power button again. This rules out a stuck remote power button sending repeated commands.

3. Try a different wall outlet and disconnect HDMI/USB devices for the test. A bad attached device can sometimes confuse startup/CEC.

4. Watch the standby light pattern. If the light changes when you press power but the screen never lights, the remote is probably being received and the problem is more likely inside the TV.

5. If it still will not start from the physical button, common causes are the power board, main board, backlight, or a shorted panel/backlight circuit. At that point it needs voltage/backlight diagnostics rather than another remote.

If you get the TV to boot normally, then you can troubleshoot the remote/pairing separately. But if the TV never turns on from its own button, a phone remote app will not help because the TV has to be fully powered on and connected to the network first.