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geekhack Community => Keyboards => Topic started by: delatroy on Tue, 07 August 2018, 05:20:26

Title: Fixing broken switch connections on Filco 104 PCB
Post by: delatroy on Tue, 07 August 2018, 05:20:26

Hello!  :)
After replacing all switches on a Filco that I have, some of the keys do not make a connection. They are q, b, n, /, left, right, down, numpad-

Here is the PCB in question:
(https://i.imgur.com/d40kADu.jpg)
(https://i.imgur.com/jcdbeUD.jpg)

The connections look good but maybe some of the traces are broken. I don't have a multimeter to check though I just ordered one.

Does anyone know where I need to rewire these keys on the board? Is there a schematic that I could look at?

Title: Re: Fixing broken switch connections on Filco 104 PCB
Post by: delatroy on Sat, 08 December 2018, 06:52:16

So I made some progress on this by testing the continuity on the broken switches:
(https://i.imgur.com/Ov4PR2s.jpg)

Results

• Numpad-: passed all
• Left: passed all
• Down: passed all
• Right: passed all
• /: passed all
• N: passed all
• B: button failed, both reds fail, both blues pass. This could be a bad switch.
• Q: passed all

Given that the local continuity is okay, can anyone advise where I should test next? Is it just a mater of following the traces upstream / downstream to check where the connection is breaking?

Title: Re: Fixing broken switch connections on Filco 104 PCB
Post by: delatroy on Sat, 08 December 2018, 12:21:40

Fixed it:
https://imgur.com/a/nKSK6Aa

Bad trace from the top right pin coming off the controller. Jumped it.
Also a pad was lifted on Q which was bridged by scraping away some of the trace to reveal the copper.