I think I may have lost a part to my mouse. There are spring-loaded contacts at the negative end of the battery compartment but at the positive end there is nothing. Was there a piece of metal here bridging the two batteries which I have dropped down the back of the sofa. Can anyone with a mouse advise me?
No, there is no bridging piece. The contacts for the positive end of the batteries are quite deeply recessed. I think this may be an attempt to prevent the use of rechargeable batteries which (sometimes, at least) have shorter studs on the positive end.
Thank you Trevor. I have found an excellent video where the repairer is not waving the mouse around with an out of focus camera so was able to see how it is supposed to be.
The recessed contacts were so shiny I thought it was perspex covers I was seeing. This doesn't make my mouse work but it does mean I have all the bits. There is ribbon cable inside which is apparently almost impossible to reconnect making repair too fiddly for my fingers so I'll possible buy another.
I bought mine second hand because I didn't want the rechargeable Mk2 version but it never worked very well and now has given up because I think the previous owner let the batteries leak and corrode the circuitry.
I took my mouse to pieces and was able to access both circuit boards without removing the ribbon cable although you have to break the contacts retaining lugs which are additional supports and are not needed. Fortunately there is no signs of corrosion beyond the actual battery contacts however as expected on reassembly the mouse is still not working. To prove the mouse was still defunct I didn't have to reattach the rubberised plastic rails which look very tricky to reinsert.
Rick Churchill 