Screen turns off when plugged in Fixed by limiting battery charge in MyASUS
Mode:l Asus TUF Gaming F15 FX506
A week ago, my laptop was repaired for several issues, including failing to power on and having no screen signal when it did. One of the repairs involved installing a generic battery.
Afterward, I noticed the screen only worked when running on battery power; plugging in the charger immediately turned the display off. Online posts suggested lowering the refresh rate (Hz), but that didn't help. My hypothesis is that the replacement battery altered the motherboard's power distribution.
The workaround is to open MyASUS and set a lower battery charge limit. Once adjusted, the screen displays properly. It sounds absurd, but it works for now.