1983 F/XT: first impressions

[modelf]

TL;DR: First-time Model F/XT owner. This board has semi-functional keys. How to fix them?

[Imgur album]

Greetings all... first, please forgive me. I did search DT and GH and found some helpful posts, but nothing that really seems to fix this problem.

After several years of owning and using 1986-87 Model Ms and more than one Model F/AT, I think I know these keyboards pretty well. I've done ten+ Model M screw mods and one foam replacement on an F/AT. Was very happy with how these projects turned out. I'm accustomed to replacing barrels, reseating springs and triaging these keyboards, especially the F/AT.

Well... I got a small bonus at work in February, so I decided to spend the money on an F/XT keyboard. I'd never typed on one prior to this. I spent a week or two lurking on eBay, VintKeys.ca and a few other places. Found everything from new-in-box XTs for $500 to a great offer on a well-used XT for $50. (It's amazing how much the prices vary.) In the end, I purchased a dirty, but physically in good condition, well-loved specimen (made in USA) for $95 plus shipping on eBay. Bonus, it included the original box.

So the keyboard arrived caked in dirt. I hand-cleaned all the parts and reassembled it. The original foam does not need to be replaced. I had to replace most of the 1u keys (with keys from a new old-stock set of F/AT keys) because of pretty severe ink and legend bleed in the original keys. Not sure what would have caused it, but I decided to change the keys out to make them easier to read since I'm still getting used to the layout.

All in all, the XT has become my favorite buckling-spring keyboard (which means it's my favorite keyboard). It reminds me of typing on a Displaywriter beam spring keyboard at a temp job in the 1990s--it's very close to that feel. It's 6.01 lbs (2727 grams) with a Soarer's converter attached. Just a shade lighter than my F/AT, but it sounds and feels better to type on (it's not even close). Of course it's better than any Model M I've used, but (to my mind) you can't really compare the XT to a Model M: the XT has a metal chassis and semi-metal case. And, it's capacitive. So, apples and oranges.

Here's my question and the main reason I'm posting: I have four keys (A, W, L, and numpad 2) that only register about half the time. They work, but only when they want to. I've reseated and replaced springs, checked the barrels and flippers, disassembled and cleaned everything. Having the same problem over and over again. Wondering what I could do to fix it? I solved my own problem. Did some further cleaning and adjustments to the springs... and now these four keys are working 90% of the time. I've noticed some very intermittent issues, such as the space bar double-registering and some other oddball problems on maybe every 500th keystroke, but a lot of that I'm just chalking up to the keyboard's age and level of previous wear and tear.

The more I type on this, the more I like it.

Here's a text blurb I included when I posted about this keyboard on Reddit (before a mod removed it):

Some background: I'm older and I got into keyboards later in life. From the '90s until 2022 I used the same old Logitech K120 that I bought at a Walmart in 1996 for $15. Got me through college, two master's degrees, multiple jobs as a teacher/professor and programmer. Finally in 2022 I landed a new job editing audio (podcasts) at night. I needed a backlit board. I grabbed a Cherry MX Red thing and went to town. After a while, I got tired of the Cherry and landed a heavily-used 1995 Lexmark Model M. I like fullsize boards and this one had everything I wanted except backlighting. Really enjoyed the SOUND and the tactical feedback. That led to a few 1986/87 IBM Model M purchases (they're heavier and better than the Lexmark) and finally to two Model F/ATs, which I bought because I kept hearing they were better than Model Ms. I didn't "love" the F/ATs, so I went back to my favorite Model M (a 1986 1390120 without lock lights). Finally... on a complete whim a couple of weeks ago... I grabbed a $95 IBM Model F/XT board on eBay... and I'm in love. Yes it has a strange layout, but man I can't stop typing on it. Love this keyboard. Occasional sticky keys and all! And it was a fraction of the price of just about any other keyboard in its "class."

[AndyJ]

Make doubly-sure the ground wire between the metal chassis and case is hooked up and has a good connection. After taking one of my F/ATs apart I had a bunch of weird problems, including some manifesting as you described, which went away when I snugged down the ground wire.

I have no idea why it should have made a difference, but capsense stuff can be weird.

[Yasu0]

I picked up an inexpensive dirty XT which has a couple of numpad keys that are like you say. They got better with normal use, but still only fire 90% of the time.

[modelf]

AndyJ... no, it's not a grounding issue, but thanks for the suggestion. But yeah, I totally agree that these keyboards (as far as Model Fs go, I've only tried the vintage AT and XT) are very sensitive to grounding. Any time that wasn't "right" on one of the boards, it would spit out total gibberish until I fixed it.

Yasu0... the one key I can't seem to fix is numpad 2. I reseat the spring, fiddle with the keycap, it works correctly for a day or two, then it starts squeaking and making a really strange rattle (not the usual buckling-spring rattle) when I push it, and then it only partially registers. I've had multiple springs in it and two barrels. Nothing seems to work. I don't think it's an issue with the PCBl... it's clean (and the key "works" when I touch it with a finger). I've cleaned all the parts (springs, flippers, barrels, keycaps); this is the one and only key that doesn't want to work.

Judging from wear on the keycaps, I would say that, in a previous life, this keyboard was heavily used by someone who really used the numpad nav keys. There's a lot of PBT wear, even fading legends, on the 2, 4, 6 and 8 keys. They probably leaned hard on the 2 key. But still, everything should be working.

[modelf]

UPDATE -- after some weeks of trying to repair the faulty numpad 2 key by reseating the spring, adjusting the keycap, etc., nothing worked. So, today I disassembled the keyboard down to the springs and barrels. I cleaned some black tar-like gunk out of the assembly (barrel) plate, then I swapped the barrels for the F4 key (which I almost never use) and the numpad 2 key (which I use a lot as the down arrow button). Then I replaced the springs on both with some NOS F/XT keyboard springs left over from a big box of IBM stuff. Reassembled the keyboard. That finally did the trick. I now have a fully-functional down arrow!