Without a schematic, repairing a switching power supply is like performing surgery blindfolded. Here is why the schematic is indispensable:
: Converts AC mains voltage into stable low-voltage DC (typically +12V , +24V , and +5V ) to power the TV's main board and microcontroller. Key components include a step-down transformer, rectifier diodes (like the STPS20H100CFP ), and various filtering capacitors. vestel 17ips12 schematic
Once 5VSB is stable, the main board sends a "PS-ON" signal (usually to pin 1 of CN903 on the schematic). Locate this pin. Without a schematic, repairing a switching power supply