Discussion:
C64 Refurb
(too old to reply)
Daniel
2020-05-04 00:36:00 UTC
Permalink
Hi folks,

My C64 has been in it's box for many months now. Priorities took hold and life
has changed drastically.

I'm getting close to starting my c64 breadbin restore project. You may recall
past posts of mine lamenting about not getting a good video output and possibly
frying a chip. Though, the conversation may have occured on a forum. I don't
recall.

That said, I will be approaching this as a complete restoration project.

My list of things-to-do:

1. Build or purchase a new C64 power supply
*which ever is cheaper and/or better
2. Retrobrite the shell
3. Thorough cleaning of everything
3. Recap the mainboard
*obtain a cap kit
4. Replace a potentially burned out chip from my stupid mistake

I have yet to replace a chip on a board and so I ask this with respect to best
practices of the restoration community. Is socketing the chip a recommended
thing to do?

On another note, I believe the rig linked below is meant solely for the
original power supply. Would it be prudent to build a rig like this for any
power supply? Or are the modern equivalents built with this sort of protection
in its design?

https://console5.com/store/commodore-64-power-saver-circuit-kit.html

I will be documenting this restoration project on my phlog as well as on here.
I hope enough of you are around to assist me with knowledge transfer as I run
into any inevitable roadblocks.

Daniel Traechin

... Visit me at: gopher://gcpp.world
Computer Nerd Kev
2020-05-04 23:25:06 UTC
Permalink
Post by Daniel
I have yet to replace a chip on a board and so I ask this with respect to best
practices of the restoration community. Is socketing the chip a recommended
thing to do?
The advantage is that if the chip fails it's easy to replace, the
disadvantage is that if the chip seems to have failed, the first
suspect is that it's just a poor contact in the socket. So easier
to fix but _possibly_ less reliable. More of a problem if the board
is likely to be bumped around a lot. You'll have to decide for
yourself what you prefer.

You might also consider installing heatsinks on some of the chips
seeing as you're doing everything else.
Post by Daniel
On another note, I believe the rig linked below is meant solely for the
original power supply. Would it be prudent to build a rig like this for any
power supply? Or are the modern equivalents built with this sort of protection
in its design?
https://console5.com/store/commodore-64-power-saver-circuit-kit.html
In theory the originals had protection built into their design, it
just tends to fail because they run too hot so the regulator chip
dies an early death. Poor quality capacitors can also fail early
and cause excessive supply ripple, more so if also overheated.

So if you're sure that the replacement power supply is well heat
sinked and uses high quality genuine components, it might be
over-kill to use a protection circuit. On the other hand if it's
something that someone's cobbled together from cheap Chinese
PSU modules bought off Ebay, then I'd suggest more caution.

My design also indicates ripple and low 5VDC or 9VAC voltage:
http://computernerdkev.heliohost.org/comiemon/comiemon.htm
http://computernerdkev.heliohost.org/comiemon/relay.htm
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Daniel
2020-05-05 15:57:11 UTC
Permalink
On 5/4/20 4:25 PM, Computer Nerd Kev wrote:

I just happened to look at c.s.cbm when I saw this reply. Just so you
know, there is a one-way exchange between fidonet and this newsgroup so,
while I posted this on fidonet, your reply never made it to me. And
other than the reply-to address, BBS fidonet gateway information is
stripped from my original post so you have no way of knowing that the OP
comes from a BBS. I believe they used to have two-way communication I
figure they disabled it due to increased SPAM issues during usenet's
heyday. If I hadn't inadvertently clicked on this newsgroup (I generally
don't), I may not have seen your reply for a long time. I'm glad I did,
must've been a psychic thing.
Post by Computer Nerd Kev
Post by Daniel
I have yet to replace a chip on a board and so I ask this with respect to best
practices of the restoration community. Is socketing the chip a recommended
thing to do?
The advantage is that if the chip fails it's easy to replace, the
disadvantage is that if the chip seems to have failed, the first
suspect is that it's just a poor contact in the socket. So easier
to fix but _possibly_ less reliable. More of a problem if the board
is likely to be bumped around a lot. You'll have to decide for
yourself what you prefer.
I'll probably do a socket if it comes down to replacing the chip.
Post by Computer Nerd Kev
You might also consider installing heatsinks on some of the chips
seeing as you're doing everything else.
Funny you mention that. The thought never occured to me in doing this
until I saw this earlier. I just forgot to mention it on my to-do-list

https://www.thefuturewas8bit.com/64-repair
Post by Computer Nerd Kev
In theory the originals had protection built into their design, it
just tends to fail because they run too hot so the regulator chip
dies an early death. Poor quality capacitors can also fail early
and cause excessive supply ripple, more so if also overheated.
If I buy a c64 PSU, it'll come from sites specific to the C64 or
retroware. Something like this:

https://commodore4ever.net/collections/power-supplies/products/commodore-64-vic-20-power-supply-atom-retro

https://www.c64psu.com/c64psu/43-157-commodore-64-c64-psu-power-supply.html
Post by Computer Nerd Kev
So if you're sure that the replacement power supply is well heat
sinked and uses high quality genuine components, it might be
over-kill to use a protection circuit. On the other hand if it's
something that someone's cobbled together from cheap Chinese
PSU modules bought off Ebay, then I'd suggest more caution.
http://computernerdkev.heliohost.org/comiemon/comiemon.htm
http://computernerdkev.heliohost.org/comiemon/relay.htm
Taking a look, thanks.
--
Daniel

Visit me at: gopher://gcpp.world
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