In this short episode Shahriar performs a teardown and repair of a Sencore PR570 variable isolation transformer and safety analyzer. One of the LCD segments of the unit does does not display.
The teardown of the unit reveals a variable auto-transformer followed by an isolation transformer. The main board contains all of the circuitry for performing over-current protection, ground leakage current monitoring and other safety analysis software. The LCD problem is easily corrected by cleaning the contacts of the LCD module. A quick experiment on an Apple iPhone charger is used to verify the instrument functionality.