[Coco] Yet Another Disk Pak Issue (was Re: Help reviving an old CoCo 2)

[John Goerzen]

Arthur Flexser <flexser at ...> writes:

[ Art replies to me saying I'm buying a FD-501 pak on eBay ]

> 
> Even if it doesn't work, might be useful as a source of chips to try
> swapping with identical ones from the other controller to see if that
> revives the first one.  A bad WD1773, the main disk controller chip, seems
> like a likely suspect.

So the pak arrived today.  I can make it work - sometimes.  About 50% of the
time, when the disk controller pak is inserted, the computer powers up to a
green screen and... nothing else.  Just an empty green screen.  Occasionally
there are other random display artifacts.  Wiggling or bumping the cartridge
seems to have an effect, so I suspect the problem is contacts on this one.

I tried cleaning them with contact cleaner and a Q-tip, and although they
weren't visibly dirty, that did get some off.  I don't want to be too
abrasive, and I'm not convinced this will really solve the problem, but --
ideas at this point?

I don't want to keep sinking money into controller paks, but there seems to
be nobody selling them other than "as-is".

Thanks,

John