S
sparkinlee
As nickblake says you should be able to pin it down by testing which does not require taking all the fronts off. But if the order of circuits on the ring is not obvious you might need to take a few fronts off in the area you pin it down to - if the configuration is really confusing take a few fronts right off and then bell test the legs between sockets to work out where the ring goes.
Then IR test each leg separately to find the fault. Once you've identified which leg has the fault, consider replacing that leg with a new cable run along a route you choose to avoid too much damage to decoration etc - don't worry about trying to dig out all the faulty cable from behind the tiles etc.
This does risk isolating anything which you've not found that is spurred off the cable you abandon, so make sure you've found all the sockets, fcus...
Then IR test each leg separately to find the fault. Once you've identified which leg has the fault, consider replacing that leg with a new cable run along a route you choose to avoid too much damage to decoration etc - don't worry about trying to dig out all the faulty cable from behind the tiles etc.
This does risk isolating anything which you've not found that is spurred off the cable you abandon, so make sure you've found all the sockets, fcus...