A useful trick I sometimes use when I have trouble following a connection (especially those which "disappear" into a multi-layer board). If you just can't figure out where a signal goes - cut squares of tinfoil, and press them against sections of the board with a firm sponge (something with enough give to let the foil seat against all the pins). Then using a good continuity tester such as Tony describes, you can quickly cover large areas to quickly narrow down where exactly a signal is located. (use foil squares sized as needed). Obviosuly you do not want the board powered at all - insure that caps are discharged, batteries removed etc. Regards, Dave -- dave04a (at) Dave Dunfield dunfield (dot) Firmware development services & tools: www.dunfield.com com Collector of vintage computing equipment: http://www.parse.com/~ddunfield/museum/index.html