K6600 door bell - partly working

Sometimes the kit works like this: It can make 1 and 3 tones. If I try 2 tones it will not work for a day - why? The same goes if I try to change tone pitch or volume. I did with success change the volume with no error afterwards. How can I debug the board? I am very new to this world and very proud of even having a working door bell.

  • hope this is the right forum

This sounds like a mechanical problem (intermittend contact, bad soldering, missing soldering, broken track or pad…) Inspect the complete assembly and wiring or better, have it inspected by a friend.