MK 171 Voice changer problem

Kits Mini Kits Range
1

Hello to all,
I have a little problem with my voice changer KIT (MK171),
when I finished assembling, I have tested the KIT, and it it worked like a charme,
but other day, when I wanted to test it again, it worked, but with some problems :

  1. Buttons seem to take no influence on the output voice
  2. There is no microphony (the phenomena when you put mic in front of the speaker), and there was microphony
    when I turned on the circuit by firrst time.
  3. The speaker is obviously more quiet than before (there is no output when you speak quietly directly to mic.)

Thanx…

2

If it worked before, it is very likely that a mechanical problem is at the cause of troubles.
Check solderings, pads, tracks, wiring etc…