Use a 1k resistor between 5VSB and PS-ON. Then check if main 12V/24V rails come up. The schematic tells you which FETs and transformers are in that path.
: Includes a bridge rectifier and filtering for standby and main voltages (12V and 19V typically). Backlight Driver : Output voltage ranges between 45V and 94V depending on the specific model configuration. Interfaces