Edifier 1280T broke down, probably issues with power supply in one way or another

So for the last few weeks I noticed the speakers sometimes making a quitet "crackling" sound when I used them. Then suddenly they didn't power down when turning the power switch off (power led stayed green and was still making sound) but they did turn off immediately when unplugging them. After using them again (without first investigating further: not smart, I know) they suddenly made a loud bang noise (I was somewhere else in the house, not there when it happened) and the house fuse blew.

So obviously I haven't plugged them in since and I took them apart but haven't found anything that looks broken (no leaking/oversized capacitors or any signs of a fire that I can see so far).

I assumed it might have been a problem with the power switch itself (because of previously mentioned symptoms) but when I test it with a multimeter it seems to work perfectly. Anyone have any ideas or can provide some help as to what might be the issue and/or how to fix it?

Thanks in advance for taking a look!