Unsolved - Pitch bend and Mod wheel not working

[rosemanster]

Any one any ideas, Just bought a Polar secondhand, is all working fine apart from both the Mod and Pitch bend wheels. They are not transmitting MIDI or responding in anyway. Pitch bend is received over MIDI though.

Have had a quick look inside, in case it was something simple like the cable had become detached but no it all looks fine.

any help appreciated, as driving me mad

thanks