High Equivalent Series Resistance (ESR) or physical bulging due to heat. High-value resistors (100kΩ+) Board works if warmed up, but won't start from a cold plug.
[ Input Rail (12V-15V DC) ] ──► [ IC Voltage Regulator ] ──► [ Regulated 5V Output ] │ ▼ [ 4-Channel Transistor Switches ] ──► [ Controlled Outputs 1-4 ] 1. The Power Regulation Stage wannien 101v0 power supply schematic verified
SECONDARY (Low Voltage Side): Transformer Secondary (0-12V-24V) → Bridge Rectifier (KBU810) → Capacitor C1 (4700µF/50V) → +V_Raw High Equivalent Series Resistance (ESR) or physical bulging
Measure continuity on your PCB: If the schematic shows auxiliary winding connected to pin 5 of IC1, but you measure it connected to pin 7 – the schematic has swapped pins. wannien 101v0 power supply schematic verified