[Coco] Unreliable Coco3

[Retro Canada]

oh yeah, cleaning the expansion board pins too hehe. TLW is a good
troubleshooting reference :)

You should check the coco3 service manual too, there is a
troubleshooting about random characters on screen.

Check the cassette port too. It might get you the state of other chips
IC7 (Cassete/DAC) and the RS-232 (IC8).

There are 2 test points on a coco3 PCB. The voltage is written right
on it. One is 5 volts. When the symptoms appear you could measure the
voltage on it if it still is doing 5V. A bad PSU could be the cause of
all your trouble too. It's hard to "remote troubleshooting as Mark
Marlette told me once ;) "

On Mon, Oct 22, 2012 at 10:04 AM, Frank Swygert <farna at att.net> wrote:
> Retro Canada went over all the easy things to check. He mentioned
> reseating/cleaning the memory chips, but forgot to mention doing the same to
> the expansion board.
>
> Other than that d/l "Tandy's Little Wonder" and go through the cartridge
> ports checks with a volt/ohm meter. In the repair sections there is a chart
> with what the voltage or resistance should be on each pin.
>
> --
> Coco mailing list
> Coco at maltedmedia.com
> http://five.pairlist.net/mailman/listinfo/coco



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