I've been browsing the Atariage forums for a long time now and with help from a lot of great posts I've modded and resurrected quite a few Atari systems. Thank you, to all of the knowledgeable and friendly people who post here.
I finally came up against some issues that I haven't been able to sort out by searching the forums. I'll start out by telling everybody about the system I have. It is a 4 port 5200, (the non VCS adapter compatible one). I bought it untested from ebay with 3 games and 4 controllers, but no power supply or switchbox. I bought an original 4 port power supply and did the power mod to eliminate the need for the all in one switchbox, (thank you Mitch and CPUWIZ). I am using the original soldered on RF cable to connect the 5200 to my TV, (I'll likely do the video mod after I sort out the issues I'm having). I've cleaned up 2 of the controllers and the buttons are working good. The joysticks were too, but that's changed. Anyhow after I completed the power mod and hooked the 5200 to my TV it looked and sounded great, no problems with any of the games I tried. However some of the controller inputs weren't reading, but the system seemed to be working great otherwise. After a while thought a new problem started. The system would not turn off with the power button and I started getting graphical errors with lockups. The power is on as soon as I plug it in, without even pressing the power button.
After reading a few posts here it seemed that I my power problem and graphics troubles were likely due to a bad 4013 flip flop. I bought a pack of 25 and have tried about half of them - no change, the problems remain. As a matter of fact even without a 4013 socketed the 5200 powers on as soon as I plug it in and will on turn off. I also still get graphical corruption and lockups after a short time too. Aside from changing out the 4013 I've also tested the power switch for continuity. It has continuity when the button is pushed and none when it isn't, so the button isn't the problem. This has me really stumped, any suggestions would be greatly appreciated.
On to problem 2 - the controller input issue. As mentioned I've cleaned and got working 2 of the controllers. So after some searching of the posts it seemed likely that my problem was due to faulty CD4052 ICs. I bought a pack of 25 and replaced the 5 that are on the board. Success! All of the buttons now work as they should. However I am having trouble with the joysticks. The joysticks worked fine initially, before I changed the CD4052s, but started to give me trouble before I did the swap and it didn't go away with the swap. As soon as I start any game it acts like the joystick is being pushed all the way down and to the right. This happens even if the joystick is centered and does not change even if I move the stick all the way up and to the left, or any other direction for that matter. It's the same with both controllers and the same with both ports 1 and 2, I have not tried ports 3 or 4. More reading on the forums is leading me to suspect I've got a fault Pokey chip. The Pokey looks slightly discolored around the edges. I don't have another to swap out, yet, but that is what I plan on trying next. I've also cleaned the pins in all 4 or the ports. Again any suggestions would be greatly appreciated.
I do own a multi-meter and a decent soldering iron, (which I am pretty good at using). I also got really lucky with the board revision in my 5200, every IC on the board is socketed, so no de-soldering required to swap out chips.
This is the first 5200 I've owned and I've got a lot of great games that I want to start playing. I know some of you guys have seen it all with these systems, so I'm hopeful that I'll be able to sort it out with your help. Thanks in advance.