Electrical advice trip switch
 

This morning about 6.30 I had the downstairs lights on in the kitchen as I went out I turned them off then back in again about 5 mins later. All the downstairs lights went off except the one in the garage. I checked the box but no switch has been tripped. I changed the complete light fitting and put in new bulbs but still no lights. Had all the switches off and checked for power but nothing going in to any of them despite the trip switch still being in the on positions.
The box was new one year ago today and the house is 22 years old so wiring should be ok.
The electrician who did the job for me hasn't called back yet as he is working in Liverpool. Any ideas as to what to look for.

Semi sorted. Electrician just called now. All the switches in the box lit up his gadget so have power. He thinks it a probably a loose neutral somewhere in the circuit. too late for tonight but will fix it tomorrow.

Ok he came back and found that it was a loose connection sort of. The electrician who wired the house when it was built 22 years ago was crap. The wire that was causing the problem had only had about 2mm of the sheath removed so it wasn't actually screwed into place, it was just resting against the connection.
I wondered why for he last 15 years every time somebody was heavy footed upstairs the lights would flicker, the wire was jumping on and off its connection. So if you have the same problem turn your power off and check all the light wires are actually screwed in.