Atari 2600 bad riot or tia?

[Smoke364]

So I recently got a 4 switch woody Atari 2600 console (1980)

 

When attempting to power it on, all I got was random patterns on screen, it changed for each game and did different stuff each time I restarted it

 

I replaced the voltage regulator, and every capacitor, as well as cleaning the power switch very well, and reflowing everything on the board and the power is good, I’ve narrowed it down to either the tia or riot chip, does anyone know?, I’m also using the adapter instead of switch box (same results with switch box)

 

also the riot chip overheats very very quickly, and taking the riot chip out and turning it on gives the same results as when it’s in the console, so I think it’s the riot but I need some help to be sure

Edited March 5, 2021 by Smoke364

[Rick Dangerous]

I think you are in the wrong VCS forum!  

[+DrVenkman]

No chip in a 2600 should get very hot. If the 6532 RIOT is internally shorted, it can cause all kinds of problems. If you have a working system that's socketed, swap the suspect chip into the good board and see if the symptoms follow the chip If so, you've solved the problem. Don't try a good chip in a bad board unless absolutely necessary, as you risk damaging the good chip with whatever killed the bad one. If you don't have a spare system to use as a testbed/guinea pig, then you should first verify power and ground connections for each of the three main IC's to ensure you don't have any shorts on the board just in case. If Vcc and Vss are good on all three, then it's probably safe to put a new chip in. If you replace the RIOT and the symptoms persist, well, TIA is the next likely suspect but a bad 6507 might give similarly screwy results.

 

Good luck. In the meantime, as you ponder your next move, here's the best reference you can get.

 

Atari 2600 VCS Domestic Field Service Manual - become familiar with it and your life of owning and maintaining your vintage 2600 systems will get immeasurably easier. 

[Blockbuster]

Did you find a solution to this? I am having same issue. I am at least getting a purple and green line to the left and right respectively.