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  • TRS-80 Model 4 Keyboard repair

    From David Jones@djones60@gmail.com to comp.sys.tandy on Fri Nov 11 14:11:44 2016
    From Newsgroup: comp.sys.tandy

    I was wondering if anyone has some suggestions. I have a TRS-80 model 4 with a membrane keyboard. The ribbon cable has two broken traces. Does anyone have any suggestion on how repair the ribbon? FYI, the ribbon cable is the same material as the membrane in the keyboard, i.e. one big piece.
    Thanks
    David
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  • From bryan.d.lawrence@bryan.d.lawrence@gmail.com to comp.sys.tandy on Sat Nov 12 11:50:06 2016
    From Newsgroup: comp.sys.tandy

    On Friday, November 11, 2016 at 4:11:45 PM UTC-6, David Jones wrote:
    I was wondering if anyone has some suggestions. I have a TRS-80 model 4 with a membrane keyboard. The ribbon cable has two broken traces. Does anyone have any suggestion on how repair the ribbon? FYI, the ribbon cable is the same material as the membrane in the keyboard, i.e. one big piece.

    Thanks
    David
    I haven't done this, but depending on your skill level with soldering irons and such, it may be possible. it also depends where the foil trace is broken. You could take a x-acto knife to cut the membrane around the open trace and solder strands from a small gauge wire and recover with heavy packing tape. Or you may be able to solder a piece of wire point to point from ckt board to connector. there are more possibles but I am tired of typing with one hand (broken arm). Post a pic and maybe a better suggestion will show up.
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  • From David Jones@djones60@gmail.com to comp.sys.tandy on Sun Nov 13 18:04:30 2016
    From Newsgroup: comp.sys.tandy

    Well the plastic isn't Mylar so it melts pretty easily. But I'm going to try and solder it anyways and see what happens. At this point, it's ether that or see if I can use a conductive glue and solder a wire down. That is assuming I can expose the conductors and get a good connection. Well my last resort idea is make a PS2 keyboard interface to the existing connector. I'm going to take it slow so I don't make thing worse.
    A little more of the story. This was an ebay item that was supposed to be working. It wasn't completely. The video was out of adjustment and the power supply had bad solder joints on the connector. Both easy fixes. The worst was a mouse had chewed on the lines going to the power switch and keyboard ribbon. That last item is the only thing that's been hard to fix.
    David
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  • From Michael Black@et472@ncf.ca to comp.sys.tandy on Mon Nov 14 12:47:47 2016
    From Newsgroup: comp.sys.tandy

    On Sun, 13 Nov 2016, David Jones wrote:

    Well the plastic isn't Mylar so it melts pretty easily. But I'm going
    to try and solder it anyways and see what happens. At this point, it's ether that or see if I can use a conductive glue and solder a wire down. That is assuming I can expose the conductors and get a good connection.
    Well my last resort idea is make a PS2 keyboard interface to the
    existing connector. I'm going to take it slow so I don't make thing
    worse.

    Be careful. My KIM-1 keyboard needed some work, and I tried to solder
    around the problem, and melted the plastic or whatever it was. So be
    careful.

    Michael

    A little more of the story. This was an ebay item that was supposed to
    be working. It wasn't completely. The video was out of adjustment and
    the power supply had bad solder joints on the connector. Both easy
    fixes. The worst was a mouse had chewed on the lines going to the power switch and keyboard ribbon. That last item is the only thing that's
    been hard to fix.

    David


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