Went detecting today and my 705 started falsing when you bumped the coil. Checked all my settings and connections all ok. Noticed if I hit the shaft it did it too. Patted the control head, waved the detector from side to side it did it also. Changed coils, no help. Checked my digging buddys 70 (with same settings) his didn't false or anything. Is this a loose part in the control head? Anyone had the same problem? Thanks and HH