HV_Medic wrote: 17 Feb 2023, 03:48
I watched your video, and my first inclination was to think your keyboard's behavior looked like a short from liquid spilled in it. Then I saw your comment that you may have drooled into the board, somehow I missed it. My guess is that that's probably exactly what happened, your saliva probably dried on the board leaving a trail of conductive electrolytes shorting something out. Your best chance to repair the board would be to de-solder all the switches, easy if you have a vacuum desoldering machine, very tedious if you have to use solder wick only. Thoroughly clean the board with isopropyl alcohol and a toothbrush, do a final rinse with distilled water, then give it a thorough few days to dry. Test each of the switches with a multimeter, replace any that are faulty, then solder the thing back together. The board is probably salvageable, it is just going to be a lot of work to get it back working properly again.
I had spoke with the company's support, and they told me the stucker was placed there by the manufacturer and they didn't care if I ripped it off. Yea it's over the only screw in the keyboard now apparently.
Looking inside, no saliva actually made it inside, looks like it rested only on the frame and that's it, so at a loss, I looked between the frame and the PCB with a small fiber camera I had. Nothing inside made it in, dry, but there was some concerns with the soldering job I did notice. The solder is not shiny anywhere, it's all hazy solder. In fact, pressing on the dip switch block made it act up further or behave depending on how I pressed on it. So I gave it a reflow, since the via's were also half filled and imo should be fully filled. Since then (and I'm typing with the keyboard right now), it's actually working just fine.
I spoke to WASD about the repair and they found it odd since the MCU only scans the dip switches on startup, but we suspect perhaps the heat from the icon fixed an issue elsewhere on the board. So maybe that wasn't the fault but it was in that area. I might honestly reflow this whole board since I'm not keen on the soldering job, it's not shiny in any way as if the solder used was either containing too much silver, or not enough heat was used.
But yea, it's actually working just fine now. Because the other concern is, before the video, it was always going into factory reset mode when plugged into the computer, which wouldn't be an issue with saliva on the key switches since that area where it was, was nowhere near the MCU nor the dip switches. So the fact it was acting as if SW4 was always on, tells me something else had to be happening.
But yea, it's working just fine now. And WASD is going to send me a space bar that doesn't have the UV coating on it since my layout doesn't have a legend on that key anyway. I was able to semi buff out the area where the UV coating wore off, but they felt after looking at the video, the way my thumb hits the spacebar, it appears my thumbnail may be scraping. And I think that's the case, because looking at my Model F XT keyboard, under a bright light I do see fingernail scrapes in the same location, but you just don't normally see it.
Huh, weird fingers, bad luck, drool, and an unrelated fault. Ironically when I first got the board they forgot an o-ring on the keyboard. So my intro to WASD wasn't exactly the best it could have been, but their customer service absolutely is, and they allowed me to attempt my own repair without voiding the warranty at all, and were happy I was able to get it working.
Another test I had explained I was doing as well, was when it was acting up, giving the PCB and frame a slight flex, and the keys that worked and didn't work would entirely change. Twist the other way and suddenly everything was working just fine. I bet there's a bad solder joint somewhere, maybe on the MCU itself.
I did notice when I did have a job while working, sometimes it would stop communicating and just repeat keys and stop within 2 seconds. That was even before last night, and I was blaming the USB hub, but now I bet it was whatever was going on, because since my reflow of the DIP switch bank it's not had a single hiccup whatsoever. Who knows now. But while I had it apart, I went ahead and cleaned the frame with all the keys off, and since it's a Hylian based keyboard, oh boy was THAT fun putting right keys back on in the right spot, since even though I can read Hylian, there's repeat letters, and R, and F, different rows, and slightly different key cap profile, so I kinda had to figure that one out. lol
Anyway, it appears to be fixed so, idk. I might still reflow the whole thing, but I don't want to tempt fate since it *is* working right now.