This Leica-M Monochrome has a sticky On / Off switch, but it's "easy" to fix. Just use a good JIS 00 screwdriver (PH00 modified) to take off the botton plastic plate.Next: use a longer PH0 for the 2 screws in each side from the botton, the 1 screw in right side will stay, the other in the battery compartment is taken out.And now ready for take off the top cover.When taken off the topcover take care of the flex cable.The sticky "fluid" was best taken away with Lighter Fluid (Zippo) and some Isopropyl alcohol.