In this episode Shahriar repairs a BK Precision 9185 600V linear power supply. The instrument is missing a power connector and therefore cannot be powered on. To be cautious, the unit is disassembled first before being retrofitted with a new connector. The teardown reveals damaged resistors at the back of the main power supply PCB. The damage points to a defective high-voltage MOSFET. This transistor is one of six devices in parallel. The impacted components are all replaced before the unit is retrofitted with a new power connector.
After power on the unit is verified for proper operation. Using a Keithley DMM7510, the power supply is calibrated and is ready for future experiments.