Columns not working after mod

Aldebaran

24 May 2023, 06:50

https://i.imgur.com/6fpFHrG.jpg
In the photo (the red area) those keys are not working. They don`t light up nor are recognized when i press them. This happened after i tried a tape mode. When i touch the left pins the lights shine dimly on the column. Is there any way to salvage this or is the pcb done?

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Muirium
µ

24 May 2023, 13:17

Imgr doesn’t work well with my adblock, so…

Image

If the whole column is out, the fault will likely be near the controller. You may be able to patch this.

SunshineRag_DT

24 May 2023, 16:12

Aldebaran wrote:
24 May 2023, 06:50
https://i.imgur.com/6fpFHrG.jpg
In the photo (the red area) those keys are not working. They don`t light up nor are recognized when i press them. This happened after i tried a tape mode. When i touch the left pins the lights shine dimly on the column. Is there any way to salvage this or is the pcb done?
If you have not done any soldering and it was working before the tape mod, I would just use rubbing alcohol and wipe down the entire pcb and especially that area, since as a random thought maybe the adhesive was conductive... I can still see some of the adhesive there on the right.

Aldebaran

25 May 2023, 00:17

SunshineRag_DT wrote:
24 May 2023, 16:12
Aldebaran wrote:
24 May 2023, 06:50
https://i.imgur.com/6fpFHrG.jpg
In the photo (the red area) those keys are not working. They don`t light up nor are recognized when i press them. This happened after i tried a tape mode. When i touch the left pins the lights shine dimly on the column. Is there any way to salvage this or is the pcb done?
If you have not done any soldering and it was working before the tape mod, I would just use rubbing alcohol and wipe down the entire pcb and especially that area, since as a random thought maybe the adhesive was conductive... I can still see some of the adhesive there on the right.
I used masking tape. I tried isopropyl alcool but nothing. Can it be fixed by soldering? I may get a kit since it`s useful for a lot of things.

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vvp

25 May 2023, 12:57

Check (with a magnifying glass or better with a microscope) whether the PCB is not damaged somewhere (scratched trace, broken part, ...).
If damaged then try to fix it (reconnect the trace, replace the part, ...).
If it looks OK everywhere then you may have caused an electrostatic damage. This typically can be fixed only by replacing the affected part (most likely the MCU or some extender, line driver etc.).

You can do some continuity measurements on the affected column traces (from the pins on the switches up to MCU or extender, ...). Measure according to the schematic if you have it. If you do not have it then you can try to guess visually from PCB ... or send it to a repair shop or just dump it to a garbage bin.

SunshineRag_DT

30 May 2023, 17:22

Aldebaran wrote:
24 May 2023, 06:50
I used masking tape. I tried isopropyl alcool but nothing. Can it be fixed by soldering? I may get a kit since it`s useful for a lot of things.
If you can figure out where the break its it could be fixable, but you would have to find it. Basically you can run a quick troubleshooting matrix.

1.) Assume it seemed to be working before tape mod, so you started with a functional board.
2.) When the tape mod was applied it continued to work while taped
2.a) If it stopped working after the tape mod was applied then likely something shorted.
2.b) If it was working fine after taping continue.....
3.) If additional solder work was done after removing the tape.
3.a) Check the newly solder connections for short or lifted traces.
3.b) If no solder work right before its stopped working continue....
4.) If it stopped working after the tape was removed but no additional solder work was done
4.a) Likely the tape removal lifted a component, either completely pulled off or lifted a trace.
4.b) See if you can located a lifted component, or push down on components in the area to see if something activates.

Sound like 4 might be your issue, but it is tough to say how to fix unless you a visible component missing or lifted connection.

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