I accidentally screwed into a cable , it tripped the RCD , I inspected the cable and all three wires appear to be OK yet when the RCD is reset there are some sockets in the house that don't work at all , some work enough to make lights show on a digital clock but not enough to turn the tv on and yet others work normally ! Any ideas would be great ?
When a screw is removed form a cable the insulation (which is pushed back) covers/springs back (Correction - the 'sheath' outer not 'insulation' inner) and hides the internal damage.
Live/line is connecting to earth somehow (by being damaged) and tripping the RCD.
Ben's Correct. It is dangerous & that's why your sensitive RCD is not behaving.
If in doubt call us out.
Mark - Fuse Electrical Services
Any damage to the insulation or cable is very dangerous. The damaged part needs to be replaced unfortunately.
The battery of tests to certify a ring main will confirm everything is working.
Sorry there isn't better news!