Well, having never experineced one of these before, one doesn't really know where to start...Very frustrating that my first 17th CU, and I get one.. :_|
Anyway, having been given good advice
here.. I preceeded to find the problem today..............
Sometimes you can't see the wood for the trees when things go wrong...
Anyway:
Landing ceiling rose (heart of the problem)
Took the bull by the horns and got Landlord to pull carpet and flooring up, immediately above (Loft conversion:^ O)
And there it was, inaccessable JB...
Supplying Neutral & CPC (plus loop lives to rose).......
(And I could see switch wire from downstairs lighting circuit aswell)
Sods law my first 17th, should get this....
Now the easy bit getting the Neutral upstairs...
*