Hi im trying to replace a old switch with new, my old switch bottom of staircase, gang 1 controlled my lounge lights off/on.., gang 2 controlled my staircase lights, with another 2 gang switch on top landing, controlling staircase lights+bathroom lights which i have not touched !!

My old switch was marked on rear as, B2, B1, A common
B common, A2, A1.. in wall behind switch i have three cables :-

Cable 1, Colours Red,Black+Earth
Cable 2, Colours Red, Black+Earth
Cable 3, Colours Red,Blue,Yellow+Earth

My new switch on rear is marked, common+ 1way, 2 way on 1 gang, and same on 2nd gang

If anybody can give wiring info i would be very grateful

Keith Huitson, April 2012