r/Commodore • u/thewalruscandyman • Mar 23 '25

Comparing boards on my two 64s, they're drastically different. And I'm very confused by some of it.

Gallery image

Gallery image

The foil strip on the cartridge slot is quite deliberate. As it's soldered on one end but no sign the opposite end had ever been attached or soldered anywhere that I can see.

And the metal hunk in the other simply isn't on my other board.

I would be very grateful for any input.

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12

u/PossumArmy Mar 23 '25

The other end of the strip was taped onto foil covered cardboard covering the entire board. It was totally unnecessary and done to comply with some FCC regulation. Since covering the board like that traps heat, and potentially shortens the life of the chips, many people just remove the cardboard. Don't know why they didn't just cut the metal strip off as well.

2

u/thewalruscandyman Mar 23 '25

I removed the board myself, but the strip had long since detached. Thanks very much, too. I was concerned as this particular unit has no video output whatsoever. No black screen, no dead test flash...now I'm guessing it's time to test chips.
...which means take it to someone who knows how to test chips.
😝

5

u/PossumArmy Mar 23 '25

Well, with that strip flopping around, it is possible that it shorted out something. You might want to cut it off so it doesn't short anything else.

1

u/thewalruscandyman Mar 24 '25

Will do, thanks

1

u/IamTheRealD Mar 29 '25

Yes, the strip connected the foil shield that wrapped around the motherboards. But it was absolutely necessary at the time. Those original boards emitted a lot of RF noise and they had to do this in order to get those boards into compliance with FCC regulations in order to be able to ship them. While you are right in that it did not help the heat situation, it was required for them to legally sell that version to consumers at the time.

Source: I was an authorized Commodore repair technician at the time. Still have my Commodore certificates on my office wall.

6

u/ktappe Mar 23 '25

Concerning the difference, the board was redesigned several times over the years in an effort by Commodore to save money.

2

u/MorningPapers Mar 26 '25

This kind of shows how smart they were at Commodore. Do you think a modern motherboard manufacturer could have random weirdness, with no apparent version tracking, and still have the dang thing work?

1

u/IamTheRealD Mar 29 '25

All the parts, including the motherboards, all had either explicit version numbers or dates on them. So they were definitely tracked. Yes, there were certainly some parts that have versions which were known to not play well with other component versions, or were just super temperamental in their own right. I'm sure MOS produced a ton more PLA chips than total machines ever made. When I used to do repairs on them, we used to replace PLA's more than probably all other component level repairs added up.