The shell of the $5 Bosch GDS 18-Li electric wrench was completely broken, the main control wire was disconnected, and the inside and outside were covered in sludge.
Fortunately, the gearbox is in good condition, the main control is good, and although it lacks carbon brushes, the motor is in good condition.
This time, the casing was repaired, labels were made, the gearbox was completely disassembled and thoroughly cleaned, the main control was repaired and the broken wires were repaired, and the motor was replaced with the original carbon brush.
Eventually full functionality is restored.