One set of 100 count foam capacitive pads for fixing broken keyboards. These are homemade in house and the 100 should cover what you need with a few extras for your convenience. These will work on keyboards from many different kinds of vintage computers. If it has a Keytronic keyboard it is likely it has a pads inside which are deteriorating and need to be replaced. Even if you have only a few keys not functioning it is likely the rest will start to go soon. It’s just a matter of time before that foam starts falling apart. I highly recommend replacing them all while you have your keyboard apart so you can get many more years of use with no worries. Here is a list of some computers which have the Keytronic style contact foam mylar pads: Compaq Portable, DEC, Franklin Ace 1200, GenRad, IBM PCjr, Kaypro II, Mainframe Terminals, Sirius 1, Sol-220, SUN Type 4, Tandy, Tektronix 4107, Victor 9000, Visual Technology 1050, Wang, Apple Lisa. I’m not certain that this list is complete, but it’s a good start.
I have repaired many keyboards using these pads myself. I have prepared a quick video demonstrating how to replace one pad in your keyboard. I forgot to mention in my video that it is easiest to have the key pressed (well raised in this case as you are looking at the back of the keyboard) when changing the pad. In my video I have it propped on a up on a pen so that the key is raised. This makes it easier to get the dental pick in the groves and around the pads. Another thing I have run across is that sometimes there is some corrosion or cloudiness on the actual board itself. Sometimes simply taking a pencil eraser and rubbing it on that conductive pad on the board will clear that right up. When you test your pads after replacing them all be sure to put all the screws back in the board, not just a few of them. You don’t need to put the shell back on, but all screws do need to be in the board or all the pads may not make contact properly during your test. The video is embedded below but as eBay will be removing this feature soon I have also provided a link. If you have any questions please send me email here through eBay and I will answer it as soon as I can.