I have to repair the BALANCE - The technician ask for the << Drawing _ Schema _ Circuits >> Unfortunately , I lost the manual . Maybe somebody could help me ?
In this sort of kit, there's a good chance it's just a faulty pot (variable resistor). Strip it down, find the pot, read the type (resistance + lin, log or whatever) and find an equivalent that will fit.
You could even try a squirt of contact cleaner on the old pot before changing it.
__________________
"Love justice, you who rule the world" - Dante Alighieri