HELP!!!@@@@ SANSAMP Volume and AMP mod doesnt work!

[askwho69]

HI all i have a big problem about my sansamp the problem is the volume is not working, also the AMP mod doesnt do any changes..i traced all the errors and re do the switch " i use rotary and following the instruction in pisotones" i looked at the schematics and cant really find the problem... i'm debugging since yesterday and didnt solve yet! any one can give some tips and advice on whats happening? by the way in mic mod also there are some squealing too .. . . . all i get is fender tube sounding thing like tweed i think. . . please help!