Hi everyone, I'm working on a repair for an LG LAC503P head unit and need the schematic diagram to troubleshoot [insert specific issue, e.g., "the power stage" or "audio output"].
| Pin | Probable Function | Notes | |------|-------------------|-------| | 1 | Vcc (+5V or +12V) | Power input, decoupled with 100nF cap to pin 8 | | 2 | Oscillator input | RC network to ground for frequency setting | | 3 | Feedback / Sense | Analog input (0–5V range) | | 4 | Reference out | Typically 2.5V or 5V precision | | 5 | Logic input A | TTL or CMOS level | | 6 | Logic input B | | | 7 | Enable/Shutdown | Active low or high depending on mask | | 8 | GND | Ground plane | | 9-12 | Output drivers | Open collector or push-pull | | 13 | Fault indicator | Diagnostic LED driver | | 14 | Soft-start cap | External capacitor to GND | | 15 | Current limit input | Voltage divider from shunt resistor | | 16 | Vcc (or second supply) | For output stage | lac503p schematic
: Connected directly to one side of the primary transformer winding. Hi everyone, I'm working on a repair for