Thanks once again Simon. Checked the bridge pickup and no 'clunk'. When I put the multi-meter (mm) across the bridge p/up leads I got an ohm reading of 1346 (whatever that means)! The mm gave readings of approx 7K for both the neck and both p/ups together (they are 'minis' from my LP hollow body from a Chinese kit), whilst the bridge p/up scored a 160K across the jack lugs (presumably therefore an 'open circuit'). I put all the wiring/pots/switch back into my LP hollow and it works properly. So the SG's bridge pickup is the root cause of all my problems. The SG is actually a GuitarAust kit from 2013 and has Wilkinson pickups, which I thought were much better than the PitBull examples; so it's a question of how come the bridge pickup is 'dead' after such a short time. Will take a look at what the supply situation is with electronics and have a go at buying new.