controller no registering inputs from triggers or analog sticks

I bought a second hand controller that was advertised as stick drift but on testing with gamepad tester it shows both sticks are stuck in 4 o clock position . attempting to move them shows no results and pressing the triggers are the same . The B button which is also on the lower board does work however as does as does L3 and R3. I suspect there is damage somewhere on the signal lines from the inputs that don't work and am looking for advice on where it could be