On Tuesday, January 16, 2018 at 4:36:40 PM UTC-8, malua mada! wrote:
LG flatron monitor with touch sensor power switch... won't turn on.
Power supply puts out 5VDC OK.

but the LED status doesn't change when you push the button?
Probably there's a trickle power supply and a bigger power supply
that runs backlights and MCU, and anything that inhibits the bigger
power supply looks like 'dead ON/OFF switch'.

Shorted rectifiers and burst capacitors, maybe fuses, are the first things
to hunt for. Low-current finger-sensing gizmo is probably an innocent bystander.