[Coco] Help reviving an old CoCo 2

[Arthur Flexser]

A pencil eraser works pretty well for shining up those contacts on the disk
controller.  Though usually, the symptom of dirty contacts is unreliable
disk operation, not what you're describing, which sounds more like a blown
chip.

Art

On Sat, Nov 22, 2014 at 2:40 PM, John Goerzen <jgoerzen at complete.org> wrote:

> Hi folks,
>
> Back when I was a kid, my parents got me a 64K CoCo 2.  They got wind of
> my project to load the data off it, and gave the whole thing to me.  So
> now I am wanting to make it work for my children!
>
> I have two main problems.
>
> #1 - the disk controller cartridge isn't working.  When I put the disk
> controller cartridge into the machine, when I turn it on, it just has a
> display with a bunch of artifacts.  The computer works fine when I start
> it without any program cartridge in it.  I also have a baseball and a
> music synthesizer add-on cartridge, and they are working fine.  So the
> problem doesn't seem to be with the CoCo, but with the controller
> cartridge.
>
> The silver contacts on it seemed to be rather dirty/degraded, so I took
> the cartridge apart and tried to scrub them.  No dice.  Any ideas how I
> might fix this?  Or where might I get a replacement cartridge?
>
> #2 - the video quality is low.  I would call it noisy.  I remember it
> being this way when I was a kid, but I always assumed it was due to the
> marginal state of the TV it was hooked up to.  Obviously that's not the
> case now.  I have it set to channel 4, and I have a screw-down to
> coaxial adapter to hook it up to a fairly decent TV.  (It's a 13"
> Trinitron.  Not a modern LCD, but I already had it, and I know it has a
> much cleaner picture than what it's showing.)  Any ideas what I might do
> to fix this?
>
> Occasionally, the TV seems to somehow lose sync, and the display goes to
> a very staticky black-and-white.  Turning the TV off and on fixes it.
> It doesn't do this with other video sources.
>
> Thanks,
>
> John
>
>
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