Locate the dual 3V/5V PWM controller chip on the schematic. Check for the following essential inputs: Must read ~19V.
Shows how power moves from the DC-IN to the battery and the rest of the board. apw70 lac391p schematic portable
When analyzing the APW70 schematic, we can break the board down into three primary functional blocks. Locate the dual 3V/5V PWM controller chip on the schematic
Switching node connected to the main output inductor. apw70 lac391p schematic portable
Use a laboratory DC bench power supply set to 1V–2V with a current limit of 2A. Inject voltage into the B+ rail and use freeze spray or a thermal camera to locate the capacitor that heats up instantly. Failed Input MOSFETs