Author Topic: [help me fix] Filco: sudden and seemingly arbitrary slew of dead keys  (Read 1927 times)

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Offline thirtynation

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[This happened back in February, but a new job and moving states has delayed my ability to deal with this until now. Since then, it has sat untouched in the factory packaging waiting to be addressed.]

I got a Filco Majestouch TKL on Amazon back in August of last year and in February several keys suddenly went out (not even 6 months of use). Backspace, Tab, T,Y, open bracket, closed, bracket, Caps Lock, Left Shift all seemingly arbitrarily decided to stop working. No trauma occurred to the keyboard (drops, spills, etc). As far as I can tell, it was entirely random.

Being well beyond the Amazon warranty period, I went to Filco's website but didn't turn up much with regard to warranty, using google translate. It also seems like a huge effort to ship it back to Japan and vice versa. I decided to void the warranty, break the sticker, and open it up to see if I could see anything wrong myself. I could find no visible flaws or shorts that jumped out at me. What may have caused this? Could it be a controller problem?

The cord pigtail/header looks fine as well.  Plus, I would think if it was a cord issue the whole board would be dead, which is not the case.  The vast majority of the keys work, and the caps lock light (one of the dead keys) even blinks on when first plugged in, but then does not respond to presses.  That sounds like it would be a switch issue, but the shear amount of keys that went out, and their arbitrary placement, makes me think it's a problem with the controller or a bad trace somewhere.

I'd really like to MacGyver this back to life if at all possible...

Offline Grendel

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  • Location: OR, USA
    • Firmware for Costar Replacement Controllers
Re: [help me fix] Filco: sudden and seemingly arbitrary slew of dead keys
« Reply #1 on: Fri, 18 July 2014, 13:12:10 »
One of the column lines has a problem, check the traces and joints connected to pin 26 of the controller PCB. Reference.
« Last Edit: Fri, 18 July 2014, 13:36:29 by Grendel »
Currently using: RK-9000WH/GR, CMS QFXT w/ Ghost Squid
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Offline thirtynation

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Re: [help me fix] Filco: sudden and seemingly arbitrary slew of dead keys
« Reply #2 on: Fri, 18 July 2014, 14:00:58 »
Exactly what I was looking for.  Thank you so much.  I'll look more closely once I get home.  I'm hoping it's just a bad or dirty pin, and not the hole.

Where can I find replacement controllers?  I also found this thread...
http://geekhack.org/index.php?topic=46700.0

Offline Grendel

  • Posts: 462
  • Location: OR, USA
    • Firmware for Costar Replacement Controllers
Re: [help me fix] Filco: sudden and seemingly arbitrary slew of dead keys
« Reply #3 on: Fri, 18 July 2014, 17:16:34 »
Note that the problem can be on controller PCB or the main PCB.

Where can I find replacement controllers?  I also found this thread...
http://geekhack.org/index.php?topic=46700.0

That's exactly where to get a replacement controller :) These are actually better than the original ones (they are programmable and feature USB full speed), w/ the exception that they don't support PS/2.
Currently using: RK-9000WH/GR, CMS QFXT w/ Ghost Squid
- I'm game !

Offline thirtynation

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Re: [help me fix] Filco: sudden and seemingly arbitrary slew of dead keys
« Reply #4 on: Fri, 18 July 2014, 18:03:41 »
I'm looking at it now and the traces, pins, and holes on both PCBs pertaining to pin 26 look impeccable to the naked eye.  Since it's all of the keys associated with that column line, it must be downstream of the last key.  I'm think I need to invest in a multimeter?  That's really the only way to pinpoint where my issue is.

Offline Grendel

  • Posts: 462
  • Location: OR, USA
    • Firmware for Costar Replacement Controllers
Re: [help me fix] Filco: sudden and seemingly arbitrary slew of dead keys
« Reply #5 on: Fri, 18 July 2014, 18:52:03 »
Not sure that would help a lot. The problem has to be either on the main PCB betw. pin 26 and the 1st trace branch to the switches or on the daughter board betw. pin 26 and the Holtech chip (an ohm-meter would help identifying the pin on the chip since the trace disappears underneath it.) Through-hole connections (aka "vias") are unlikely to cause problems (although not unheard of), so I probably would start w/ resoldering pins 26 on the main and daughter PCB's and carefully checking/resoldering the pin on the Holtech chip this signal is connected to. If that doesn't fix it, verifying the signal via measurement would be nice but I probably would just get a replacement controller.
Currently using: RK-9000WH/GR, CMS QFXT w/ Ghost Squid
- I'm game !