[Coco] Weird CoCo3 problem...

[Arthur Flexser]

I vaguely recall something like this happening to me years ago that was
fixed by replacing the 6809.  If this machine and one of your others has had
the 6809 socketed, it would be easy enough to swap in a 6809 from one of the
other machines and see if the problem goes away.

Art

On 1/1/10, Brian Blake <random_rodder at yahoo.com> wrote:
>
>
>
> All of these new developments on the CoCo front finally lit the fire under
> my arse to set up real hardware again. Besides my repack project, I have 3
> other CoCo3's, two with 512k upgrades (one C9 and one PBJ) and one 128k. The
> one with the C9 upgrade works fine - can load and play Sockmaster's Donkey
> Kong.
>
> The one with the PBJ upgrade, not so... At boot, it comes up as it should
> with the proper display. However, any floppy commands are met with no
> response from the floppy drive (with an FD-502 controller) at all. Almost
> like the drive is off. The drive responds as it should in the other two
> machines. Upon removing the top case and k/b, I saw two wires, each had been
> soldered to opposite sides of R23. Now, under the keyboard, is another wire
> with alligator clips on each end, and the clips are holding on to the bare
> end of the wires soldered to R23, effectively bypassing the resistor. I'm
> looking for the PBJ instructions, pretty sure I have them, to find out if
> this is called for. I can also see where C65 & C66 have been cut and
> re-soldered. I have reseated the GIME and the PBJ memory chips, and cleaned
> the 40 pin connector.
>
> Any other suggestions? My 100MHz o'scope bit the dust so I don't have that
> tool any more (anybody have a CRT for a Leader 3 channel 100MHz scope??)
>
>
> Thanks,
>
> Brian
>
>
>
>
>
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