electronicsRepairing a Husqvarna QC330 battery charger
Husqvarna isn’t known for its customer care. In general you have two options when a Husqvarna product dies: buy a new one or try to repair it yourself. If you choose the last option, you are on your own when it comes to their battery powered tools. Of course they do not provide any technical information about the electronics.
2024-06-17
The problem
The Husqvarna QC330 battery charger does not work at all. None of the LEDs light up, the charger appears to be dead. When plugged in, a barely audible hissing sound can be heard. It could be a switched mode power supply failing to start up.
Finding the fault
I only could find one mention of a repair attempt on the internet. A person called L.A Consertos made a video. Unfortunately the video is in Portuguese. But with some perseverance, I could understand it well enough to know what the problem with his device was: a shorted Schottky diode. Could it be my charger had the same problem?
Attempting to repair
After removing the rubber feet, four screws must be removed to open the housing. A further four screws hold down the PCB. After removing the PCB I measured the Schottky diode, an SS110, and found that it was indeed shorted. This rectifier diode is part of the power supply of the secondary charge circuit. The electrolytic capacitor next to it is the smoothing capacitor and could also be damaged. Therefore, I removed the diode as well as the capacitor and cleaned the soldering pads of the PCB. Then I measured the capacitor with an LCR meter just to find that it was in perfect condition. So it appears that only the diode is damaged.
It could be an coincidence that my unit had the same problem as the unit of L.A. Consertos. It could be a design fault of Husqvarna. But it could also be a manufacturing fault in the diode itself. Without proper documentation from Husqvarna, we shall never know.
Repaired
Replacing the defective diode solved the problem and the charger is working again. It is unfortunate that without proper documentation from the manufacturer and without a repair attitude among the public, broken devices which could easily be repaired end up in landfill.