Atari Not Reading Games

[INTV123]

I have both a Gemini and a 2600 4 switch that both won't read carts inserted into them and just give garbage on screen and make noise. Tried bending and cleaning the pins with no improvement. Is this a bad cpu or possibly broken solder joint? couldn't find any info on this.

[The Mr. Video]

You should definitely try reflowing solder on the Gemini's cartridge port as the solder tends to crack on areas such as the joystick ports, power jack, and of course the cartridge slot. I've never owned or repaired a 4 switch Atari, so all I can suggest is to open it up, inspect the board, and reseat any socketed chips. Someone else with way more knowledge on 4 switch 2600s could probably go more in-depth on what might be causing the problem and how to fix it.

[vcsrocks]

16 hours ago, INTV123 said:

I have both a Gemini and a 2600 4 switch that both won't read carts inserted into them and just give garbage on screen and make noise. Tried bending and cleaning the pins with no improvement. Is this a bad cpu or possibly broken solder joint? couldn't find any info on this.

Both with the same problem is a bit suspicious though.

 

How many different carts did you try?

[RetroB1977]

I heard a bad TIA chip could cause this, I'm not an expert though. You might try checking continuity all over the board to make sure nothing is cracked. If the chips are socketed you could try chip swapping with a working machine (if you have one).

[jer10571]

If it's on both units, I would start with the cartridge your using. It is possible you have 2 broken units, but both having the same problem? How many game carts have you tried? Are they Atari games or a Harmony cart?

 

I just repaired a 4 switch that ended up having a bad RIOT chip in it. So if you have another machine you can swap chips out with, you can either rule out or confirm a bad chip.

 

The Gemini is famous for cold solder joints, so I would re-flow everything on that. Inspect and possibly do the same on the 4 switch. A couple years back one of the guys at work had a 4 switch that wouldn't read cartridges correctly. It ended up being a corroded lifted trace on the back side of the board where the cartridge slot is soldered to the board. I was able to fix it with a bodge wire.

 

That being said, I would inspect all the traces as well. These things were abused by a lot of kids (me included) and at some point someone (I remain unnamed) could've spilled some 'Soda Pop' or something in it. Just take it apart and inspect everything with a magnifying glass.

 

Also, while your in there, if you have the ability, replace the capacitors in it. It's easy to do. I just did 2 of them.