Atari 7800 Plays 2600, Not 7800 - Help? [PIC OF BOARD ADDED]

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Re: Atari 7800 Plays 2600, Not 7800 - Help? [PIC OF BOARD AD

Post by Hobie-wan »

I'd think that there's maybe a pin that the 2600 cart's don't use that the 7800 ones do, so getting a signal on that line lets the system know to run in that mode. SInce you've cleaned the pins, check continuity on pins from the plug side to the solders on the board perhaps? Maybe find a schematic that talks about the selection pin or method?
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Re: Atari 7800 Plays 2600, Not 7800 - Help? [PIC OF BOARD AD

Post by Jagosaurus »

Hobie-wan wrote:I'd think that there's maybe a pin that the 2600 cart's don't use that the 7800 ones do, so getting a signal on that line lets the system know to run in that mode. SInce you've cleaned the pins, check continuity on pins from the plug side to the solders on the board perhaps? Maybe find a schematic that talks about the selection pin or method?
That's a good point. I was thinking more of a chip set required. Pins look okay to my eyes at first glance but I'll dig for some diagrams.
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Re: Atari 7800 Plays 2600, Not 7800 - Help? [PIC OF BOARD AD

Post by ExedExes »

As an aside, thanks for not giving up on this. It was neat to see the 7800 board and the chips there. I want to see this fixed as much as you!
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Re: Atari 7800 Plays 2600, Not 7800 - Help? [PIC OF BOARD AD

Post by Jagosaurus »

ExedExes wrote:As an aside, thanks for not giving up on this. It was neat to see the 7800 board and the chips there. I want to see this fixed as much as you!
I enjoy breaking down systems so I'm enjoying it. I received this as a gift so all is well if it'll only play 2600... I'll just buy 2600 games that fit the slot (not all do like Tiger vision carts) & enjoy those! The 7800 library is interesting to me though so I'd like to fix it.

I'm going to look into pins/connection to board as Hobie suggested, as well as the Maria chip (which the 7800 titles use) per the guys @ Atari Age.

Man, the RF shield was a hooker to get off. Took me 15 minutes :D
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Re: Atari 7800 Plays 2600, Not 7800 - Help?

Post by Jagosaurus »

Okay, broke this out again today and upon close inspection...

The board has three marker strikes on it (two black, one yellow) & the area housing the RF hook up has the same marker "loop" that was on the RF shielding.

The guys over at Atari Age hadn't seen the first marking I noticed before (on RF shield) so my guess now is that it was broken and repaired by Atari or a hardware shop at some point in it's life, long ago.

Thoughts? I can take picks if you want to see more marker :] original marker I noticed:

Image

Any1 know which chip is Maria? All the chips look fine to the naked eye.
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Re: Atari 7800 Plays 2600, Not 7800 - Help?

Post by ApolloBoy »

Jagosaurus wrote:Any1 know which chip is Maria?
It's the longest chip on the board, located on the left-hand side.
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Re: Atari 7800 Plays 2600, Not 7800 - Help?

Post by Jagosaurus »

ApolloBoy wrote:
Jagosaurus wrote:Any1 know which chip is Maria?
It's the longest chip on the board, located on the left-hand side.
I'll take the shell off & give Maria a closer look this weekend.

Wait.....
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Re: Atari 7800 Plays 2600, Not 7800 - Help? [PIC OF BOARD AD

Post by Jagosaurus »

Mark on the RF housing I mentioned:
Image

Marks on the board:
Image

Think I can say it was worked on in the past.

And here sits the issue I believe. Some of Maria's connections don't look attached to the board. See upper left:
Image

Thoughts? :?:
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Re: Atari 7800 Plays 2600, Not 7800 - Help? [PIC OF BOARD AD

Post by Hobie-wan »

What about the solder on the bottom of those pins?
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Re: Atari 7800 Plays 2600, Not 7800 - Help? [PIC OF BOARD AD

Post by Jagosaurus »

Hobie-wan wrote:What about the solder on the bottom of those pins?
Yeah that's what I was seeing also. Might be worth borrowing an iron from someone @ work or finally buying one.

Guys on Atari Age also pointed out the same. We likely found our issue! Step one of the problem lol.
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