This is today’s egregious failure of cheap and poor quality goods, in the case a Digitor A9734 mini stereo system.
It came in for recycling. When tested on the bench it drew a few watts but there was no power indication. I took it apart and look what I found!
The loose wire must have been only just hanging on underneath the blob of solder where it should have been. I soldered it back on and soldered it properly. It then burst into life on a radio station. The volume control was scratchy and one speaker was giving intermittent output. I spent a LOOONG time trying to fix it by inspection and by soldering but as the hours (ok tens of minutes) ticked by the fault got progressively worse. It was awful to fault trace. I eventually gave up and went home.
The next morning I thought I would give the tape and CD player a test. The tape player chewed up a good tape and the CD player wouldn’t spin up the CD.
So I grabbed the thing by its cables and frustratingly threw it into our dismantling department!