Author Topic: Help with Red Scarf 3 unresponsive key  (Read 1759 times)

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Offline Checkfield

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Help with Red Scarf 3 unresponsive key
« on: Tue, 12 June 2018, 14:37:41 »
The 4 key on the number pad is not registering when pressed. I tried replacing the switch and following traces with a multimeter but I'm not really sure how the board works. It looks like the lower switch pin is connected to a diode but I can't figure out where the top connection leads.

Offline suicidal_orange

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Re: Help with Red Scarf 3 unresponsive key
« Reply #1 on: Wed, 13 June 2018, 09:41:48 »
As it's only one switch randomly in the middle it sounds like a faulty diode - set the mutimeter to continuity mode and it should only show with the probes connected one way, not when you swap them.

If the lower pin is the one connected to the diode the higher one should be connected to another switch's higher pin.  From the few traces I can make out in the pic it looks like the diodes connect across so it probably connects to 7 and 1?

If the diode is good and it's not connected to 7 and 1 please post a picture with the shiny bit on the affected switch as it makes it much easier to see the traces :)
120/100g linear Zealio R1  
GMK Hyperfuse
'Split everything' perfection  
MX Clear
SA Hack'd by Geeks     
EasyAVR mod

Offline Checkfield

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Re: Help with Red Scarf 3 unresponsive key
« Reply #2 on: Wed, 13 June 2018, 13:09:36 »
Thanks for the advice. The top connector also connects to switch 1 and 7 and the traces show no resistance on the multimeter.  Testing the diode showed that it works the same as the other diodes. I also desoldered some switches to look at the top of the board and D33 is connected to D32 but the trace is in tact when tested as well is the connection to the D32 diode..

Offline suicidal_orange

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Re: Help with Red Scarf 3 unresponsive key
« Reply #3 on: Thu, 14 June 2018, 03:15:53 »
If everything's connected as described it should work, have you tried shorting the two switch pins with something (piece of wire, tweezers, scissors...) and seeing if that registers as a press?  Faulty switches are rare but could happen.  Another option would be the key being unassigned in firmware, but again this sounds unlikely as it's a position everyone would use...

I've moved the thread in case anyone who's familiar with this board knows some quirks I don't, people with soldering irons may not see it in keyboards.
120/100g linear Zealio R1  
GMK Hyperfuse
'Split everything' perfection  
MX Clear
SA Hack'd by Geeks     
EasyAVR mod

Offline Checkfield

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Re: Help with Red Scarf 3 unresponsive key
« Reply #4 on: Mon, 18 June 2018, 21:53:27 »
Yeah, I tried shorting the switch and redoing the keyboard layout flash and still nothing =/