On Q2 there are markings J1 and further lying on the side 4. Under J is a dot. Probably BSS138.
I am struggling with just such a board. The hoover was supposed to switch off after 5 seconds, but in my case it obviously worked. Nevertheless, I dismantled the module, looked through, found nothing suspicious. Now the power supply is not working properly.
Module nasty to repair - everything in a flood, hard to see or measure anything, tracks peel off after heating twice.
Edit: .
Successfully repaired the power supply, the TNY was damaged due to a short circuit on the 5V line which I inadvertently made by re-soldering the capacitors. It works, with an incandescent bulb, on a load it shuts down after a few seconds when the soft start finishes, but with a 600W heater it works fine. We'll see how it does with the motor. If I were repairing this again (hope never), after desoldering the top board, I would shorten the pins connecting the boards and insert the in-line sockets on one side, so that it is easily detachable. Now after desoldering 3 times, there are no vias and I have jumper-wired paths.
