[Coco] Coco1 repair parts ?? & Results of Repair!!

[Robert Emery]

> > So I changed tacks... rather than trying to make the broken one work,
> > I'll put chips into the working one until it breaks. Not only the
> > SAM chip, but all the ram died as well.
> > The dead one has 8040517's and the good one has 8040665(?).
> > Can these be intermixed? CoCo was dead with any one of them in the board.
> > 
> > At any rate, by putting the good SAM & RAM into ol'grey, I got to see her
> > cursor flash again, so I know she's fixable.
> > 
> > Bob
> > 
> 
> I don't have all the info needed to answer this. The 8040665 part # is 
> listed as 32K RAM, 8040016 as 16K RAM. 8040517,<snip>...
> I don't have a reference for that number...
> ...
> My guess is that you may be trying 4K RAMs on an F type board.
> You're sure both boards are type F? You're sure the "bad" board did work 
> for you at some time? Are the jumper settings the same on both boards?

These are both definitely 64K F boards. My original one (ol'grey) was purchased
as a 32K ECB machine, less than a year before the new white case 64K CoCo's
came out (almost $200 cheaper... grumble.. grumble..) I recently acquired the
white-case for free, so I guess it all balanced out.

Like I said, replacing the SAM and *all* the ram chips revived the dead
machine... but I put them back in the white case. At least I know.

BTW, the green/purple artifacting on this machine was restored to normal
(red/blue) by removing the composite video driver. So the suggestion about
adding a trimmer cap somewhere or other would probably work if I ever need to
put that back in.

cheers,
Bob


		
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