GH60 and voltage problems

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maxmalkav
dye hard

07 Jul 2019, 15:58

I had laying around an original GH60 PCB (from the original GB, that one that went South and was salvaged in extremis), so I decided to solder some switches and put it into use.

Before starting I tested the PCB and it seemed to be working (basic keys, some modifiers, etc). When I finished the soldering process, I see the R_SHIFT key is not working, so I started to troubleshot it with my multimeter.

After texting several things, I see the following:
  • the R_SHIFT switch is physically fine, closing the circuit when pressed
  • the key diode seems to be also ok
  • there is continuity between the key and the microcontroller pads
  • when connecting the keyboard to Linux, I cannot detect any keystroke using commands such as xev
When further checking the PCB, I have observed that 3 of the 5 rows are just receiving around 0.7V, while the other two are getting 2.5V. The rest of the keys are and modifiers are working just fine, except for the right shift.

Do I have a faulty microcontroller? (it will be the second one this year :-/ )

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maxmalkav
dye hard

07 Jul 2019, 17:12

Nevermind, it seems it was a firmware issue. I was initially using EasyAVR. I decided to give it a try to GMK and all the keys are working just fine (which is a huge relief).

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