Tandy TRS-80 Model 4

This sounds as thought it might be slightly differnt to my keyboard. I only rememebr 2 contacts per key. On the other hand, when I ordered a replacement keyswitch for my Model 3 (about 20 years ago), I did have to specify the brand of the keyboard PCB (Radio shack apparently bought these in). The keyboards in oth my M3 and M4 are ALPS brand, FWIW. The reason I mention this is that dismantling the switches themselves will vary between brands. The good news is that (at least for the ALPS keyoard), it's a single-sided PCB, bot plated through. So it desolders quite easily, The bad news is that it's a cheap SRBP oard, and the traces lift all too easily. I've completely sesoldered several keyboards for repair. It takes me an afternoon to get them apart without damage (and a lot less time to get it back together again). I guess if you need soldering practice, though, this is not a bad project ot undertake. There arer no ICs on the keyoard PCB, so there's no risk of static damage, and the parts are not particularly thermalliy sensitive. I don;t know what drives you have (Tandon TM100s were fairly standard), but if you take them significantly apart, you'll need an alignment disk and 'scope when you come to put them back together. Again, something that doesn't worry me _at all_ now, but it might be a problem for you. If you want to take the drives apart to clean them, let me (us?) know the model number (or any markings on them). I can then give you an idea what what you can take off without losing the alignment. -tony