Author Topic: key stopped working - running out of ideas  (Read 2469 times)

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Offline Geroximo

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key stopped working - running out of ideas
« on: Tue, 31 January 2023, 17:51:28 »
I have a KBDfans67 Lite V3 ISO hotswap.
A couple of weeks ago my spacebar started acting up: It would sometimes not register.
Today I completely disassembled the keyboard, cleaned it, put it back together and now the spacebar doesn't work at all. Everything else is working perfectly fine.

What I already did to troubleshoot:
- Made sure it's not the switch that is defective
- Re-Flashed with the correct software "kbd67 mkii ISO rgb via.bin". keyboard is configurable in VIA
- Cleaned everything with Isopropanol Alcohol
- Re-flowed the solder joints
- Made sure the diode is ok by switching it with a different one from a working key
- Tested with tweezers to rule out a faulty hotswap socket

I basically don't know what else to do ... How can a key just stop working like that, every solder joint seems fine, diode is working, the switch itself is working, hotswap socket is working, everything else on the keyboard is working, but the spacebar won't register anymore.

What else can I try to find the problem?




Offline dellmodelm

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Re: key stopped working - running out of ideas
« Reply #1 on: Tue, 31 January 2023, 19:08:17 »
Sounds like it could be some kind of liquid damage.

Offline Geroximo

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Re: key stopped working - running out of ideas
« Reply #2 on: Wed, 01 February 2023, 09:48:03 »
I desoldered the hotswap socket, cleaned the contact patches with isopropanol, everything looks perfect and clean.
I'm holding my tweezers directly onto the pads but it just won't register.
Mechanically everything seems to be fine, but my keyboard for some reason acts like this key doesn't exist.
Re-flashing, mapping different functions there, nothing helps.

At this point I assume that moisture got into the Microcontroller and ****ed something up in there, probably unfixable .... I can't explain it any other way ...

Offline dellmodelm

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Re: key stopped working - running out of ideas
« Reply #3 on: Wed, 01 February 2023, 13:29:40 »
Yeah this sounds like a case of moisture getting inside there. Maybe try replacing what you can, that might fix it.

Offline Maledicted

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Re: key stopped working - running out of ideas
« Reply #4 on: Thu, 02 February 2023, 04:50:11 »
I'm far from an expert, but did you check for continuity between one contact of the hot swap socket and the diode and then from the opposite contact and wherever the trace for the other contact leads in the matrix? There might be trace damage you don't see, which could be fixed by soldering a jumper wire between any two points that should have continuity that you cannot find it at.

If there does end up being trace damage, it was probably caused by the hot swap socket putting too much stress on the contacts on the PCB and could probably use some reinforcement if you get it working with a jumper wire.

I don't know anything about that board, but I find it hard to believe that a problem with the controller would just kill the spacebar and that's it, especially if the problem was intermittent until you took the whole thing apart again.

Have you got any flux? Those solder joints look pretty crusty.
« Last Edit: Thu, 02 February 2023, 05:04:37 by Maledicted »

Offline tp4tissue

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Re: key stopped working - running out of ideas
« Reply #5 on: Thu, 02 February 2023, 18:22:36 »
Check continuity across the whole path, if the switch tests ok, then it's the board.