Never worked on a -A, but I've had a -B in bits, and I think the keyboards are mechanically similar. So here goes (from memory) Thake the keyboard out of the machine (you've done that..) then take out the screws on the metal plate o nthe udnerside I think there re 3 screws, but it's been years... Then take off the plate. The cble grommet goes into a slot in said plate, so you can slide it out to free the baseplate. Next take off the bezel. It's held on by screws between the toggle switches. Now to remvoe the electroncis. Start by removing the 2 fixing screws for each toggle switch. Looen the nut on the decimal position selector (this needs a thin spanner) and then free that switch too. Take out the remainign screws o nthe PCB and it all comes out. YOu can now see if it's the swtich or key that is seized. If it is the key, whatever you do, don't pull keys off a 9100. You will break things. The keys have a little locking barb/hook which has to be feed. For this reason you have to remove more keys that you might think. Anyway, use a small screwdrive to free this barb, then slide the key and metal rod out. The rods do not come off the keys. There should be ao O-ring on the metal rod (Size 006 IIRC). you may want to replace the complete set while it's apart. If there is corrosion on the metal rod, try cleaing it with very fine wet-n-dry abrasive paper. If the switch (on the PCB) is the problem, then from what I rememebr ,the moving contact can be freed andremoved. Sometiems desoldering the switch and removign it from the PCB helps This part of the machien is relatively simple so you should be able to fix it. -tony