Slightly out of topic question

[Francois Dion]

Might as well pick a complete C64 in a Goodwill or equivalent for a few
bucks...
Also, I remember that Master Vox in Longueuil, QC, Canada used to have
a gadzillion power supplies for the C64 and I think Texas Instrument 99/4a
and they had those for like $4-5 canadian...

Jay Martin wrote:

> Usually removing a cartridge while the unit was on would cause the power
> supply to spike.  The C64 used a 7805 type regulator that does not contain
> protection for this.  What usually happens is the power supply suddenly
> decides to oscillate at around 8 volts.  This then fries most of the RAM
> chips (they didn't have much protection in those days).  You will probably
> have to replace the power supply and the RAM chips.  But try just the power
> supply first.  Believe it or not, even though the power supply is
> non-fixable (unless you got a real early one) and has a "brick" of epoxy
> covering all the components (causing the eventual demise of the regulator
> due to it's inability to dissipate the heat) they then put a FUSE in there
> (in the middle of the epoxy).  It **COULD** just be that blew..but you will
> most likely not be able to replace it (unless you have some solvent to eat
> the epoxy away.)
>
> Try the power supply and then the RAM chips.
>
> Jay Martin
> P.S. I speak from a ton of experience, I used to work as a repair tech for
> Commodore equipment.
>
> > -----Original Message-----
> > From: gronda_a at starnova.it [SMTP:gronda_a at starnova.it]
> > Sent: Monday, October 05, 1998 4:53 PM
> > To:   synth-diy at mailhost.bpa.nl
> > Subject:      Slightly out of topic question
> >
> > Hello, I've got an old Commodore C64 (that it's also in some way an
> > analogue synth!) to repair.
> > Does anybody know what get fried pulling off a cartridge while the unit
> > is powered on?
> >
> > Thanks.
> > Andrea

--
Ciao,
Francois Dion (francois at hyperreal.org)