Atari 7800 cartridge PCB experts needed:

[birdie3]

I have a Basketbrawl cart that has a few problems and I need some advice on how to get this cart working properly. Could one of the Atari gurus please help me??

 

Today I picked up a new 7800 at my local flea market and wanted to try a game or two. My Basketbrawl has never worked properly so I though that I would try it in my new machine with hopes that it would now start to work properly. Not a chance.

 

I eventually get really pissed off and open that cart to see if maybe there is some damage. It actaully appears as though there may very well be some damage and this is where I need help. I will try to describe:

 

-the 104AEC 25V resistor at point C1 directly to the right of the biggest ROM chip is partially smashed

 

-the top right chip labelled GD74LS08-9021 has one of her pins sticking out (likely a manufacture defect) where it looks like instead of being in the hole, it is flat against the board and probably not making a good connection at point C3.

 

Could this cause the game to not load up properly?? The problem is that the game is perfectly fine up to where you select the players etc.. after that, the screen locks up at the start of the brawl court scene and the sprites looks all garbled with the playfield being toally out of whack looking. It totally locks up and the game will not proceed beyond this. Could someone please give me some suggestions or offer a solution?? Thank you.

[+Mitch]

You called?

 

I would say the loose pin on the 74LS08 is the culprit try soldering it in and see how it works. You may as well replace the capacitor at C1 as well. There's a chance that it could be affecting it but not as likely.

 

From your description it sounds like a C300595 board, am I right?

 

Mitch

[birdie3]

Thank you...Yes. C300595 Rev A.

 

I am not a soldering pro so I will be nervous doing this. Any tips?? I have a tiny tipped gun with a wick. It almost seems like I need a clamp or something when it comes time to pull the chip out so I don't smash the damn thing.

[+Mitch]

How is the pin bent? Is it under the chip or sticking out? From your first post it sounds like it is sticking out.

Also, you don't want to solder it to the hole at C3. There should be a hole directly underneath the edge of the chip where the pin is.

If you look on the bottom of the board in that area, you should see where all of the pins from that chip are sticking through the bottom of the board. There should be an empty hole with solder in it between the other pins. Use your wick with the soldering gun to get the solder out of the hole. If you haven't desoldered anything before, basically you just need to lay part of the wick directly over the hole and heat that section of the wick. The wick will suck the solder out.

After you get the hole clean, see if you can get the pin to go into the hole. It may be difficult with the rest of the chip still soldered down. If you can't get the pin in then you will have to unsoldeder all the pins on the chip. After you get the pin in the hole you will need to solder it down as well as any other pins that you unsoldered.

Good luck.

 

Mitch