New Horizon Posted May 30, 2017 Share Posted May 30, 2017 Hi! I'm new to the forums, so please excuse me if I initially misstep in any way. I pulled my old Atari 2600 out of storage recently. I've had it since 1980. When I tried to run it 7 years ago, all I got was a very snowy picture with colours and varying noises. I understand this is considered normal when you fire up the system without a game, but this was happening with a game plugged in. I tried all 15 of my cartridges in fact. I am doing system refreshes on all of my old consoles, so I purchased a refresh kid for my 2600 from Console 5. Replaced various capacitors and components, including the voltage regulator and power in jack. I had a spare Atari 2600 JR, so I desoldered the TIA and RIOT chips off of it and swapped them in to see if they would make any difference, but they didn't...which isn't surprising I guess since the JR was giving the same wavy lines and noises. The RF output on the 4 switch is terrible, so I got the parts to do a composite AV mod so I can actually get a clear view of what is appearing on the screen. Anyway, does this sound like the riot chip to you folks? I've tested the voltage going to all the chips and the voltage coming from the new regulator, and they're all spot on...so I'm not sure exactly what else to try. Thanks for your time Quote Link to comment Share on other sites More sharing options...
Jeremy Popp Posted May 30, 2017 Share Posted May 30, 2017 Did you verify you were on channel 2 or 3 using the selector switch? - just trying to rule out anything easy... also, did you clean the cartridge slot? Quote Link to comment Share on other sites More sharing options...
+DrVenkman Posted May 30, 2017 Share Posted May 30, 2017 Clear, in-focus photos of the board would help diagnose the issue(s), as would a photo of the screen of the TV (tuned to the correct channel!) with an easily recognizable game plugged in and the system turned on. Quote Link to comment Share on other sites More sharing options...
New Horizon Posted May 31, 2017 Author Share Posted May 31, 2017 Sure, I'll take some pictures or even video and post them sometime tomorrow. I have already AV modded the system to eliminate how snowy it was. At least now with composite video, the wavy lines can be seen clearly. hehe Basically, what I'm seeing is what appears on the screen if you fire up the system with no game inserted. I haven't given the cartridge slot a thorough cleaning yet, but I'll try to do that tomorrow night as well. Thanks for the suggestions. I'll get back to you tomorrow. Quote Link to comment Share on other sites More sharing options...
Osgeld Posted May 31, 2017 Share Posted May 31, 2017 no the riot chip is pure digital, what you describe sounds like analog interference, which points me to a rotten cap or power supply have you tried a different power supply in the 9-12 volt DC range Quote Link to comment Share on other sites More sharing options...
New Horizon Posted May 31, 2017 Author Share Posted May 31, 2017 (edited) Hi Osgeld. I checked the voltage with a multi-meter and it was giving me a solid 9 volts. I checked the voltage going to the chips and they were solid at 5 volts. I'll see if I can locate a substitute power supply for testing though. As mentioned above, I installed a refresh kit from consle5.com which replaces the most common problem caps, as well as the power jack, and voltage regulator. Here is the kit in question. https://console5.com/store/atari-2600-total-refresh-kit-new-capacitors.html I was having the same issues prior to the refresh kit sadly. I see the same issue whether a game is plugged in or not, the standard Atari noises and varying screen patterns. The AV Mod I did last night cleared up the snowy picture though. Edited May 31, 2017 by New Horizon Quote Link to comment Share on other sites More sharing options...
New Horizon Posted May 31, 2017 Author Share Posted May 31, 2017 (edited) Here are some shots of the board. Please excuse the quick and dirty AV Mod. Thanks again for the help everyone! Edited May 31, 2017 by New Horizon Quote Link to comment Share on other sites More sharing options...
+DrVenkman Posted May 31, 2017 Share Posted May 31, 2017 Basically, what I'm seeing is what appears on the screen if you fire up the system with no game inserted. /quote] Ugh. Don't do that. . Without a rom program to tell the TIA what to display all you'll see is digital noise or a black screen. Plug in a commonly recognizable game so people can see what you mean and compare to what the game SHOULD look like. Quote Link to comment Share on other sites More sharing options...
New Horizon Posted May 31, 2017 Author Share Posted May 31, 2017 (edited) Ugh. Don't do that. . Without a rom program to tell the TIA what to display all you'll see is digital noise or a black screen. Plug in a commonly recognizable game so people can see what you mean and compare to what the game SHOULD look like. Haha. That's not what I'm actually doing. I'm just saying that what I'm seeing when I put in 'any' of my games, is the exact same thing that happens when there is no cartridge (digital noise or a black screen or other random pattern). There's nothing to compare the game to when I put a cartridge in. It's as if none of the games are being seen / loaded. I must have around 25+ games and none work. I can't imagine them all being dead. I wonder if maybe I need to reflow any of the older connections that didn't get replaced? I'll also see about picking up a new adaptor that can put out the correct voltage, just to be sure. I'm at work now but will try to post a video of what I'm seeing late tonight. Edited May 31, 2017 by New Horizon Quote Link to comment Share on other sites More sharing options...
SignGuy81 Posted June 1, 2017 Share Posted June 1, 2017 Set your your meter to AC and check pin 11 of the TIA and come back with what you have. Quote Link to comment Share on other sites More sharing options...
New Horizon Posted June 1, 2017 Author Share Posted June 1, 2017 Set your your meter to AC and check pin 11 of the TIA and come back with what you have. It looks like it's around 3.5 or 3.6 on pin 11. Assuming it should be higher? Quote Link to comment Share on other sites More sharing options...
SignGuy81 Posted June 1, 2017 Share Posted June 1, 2017 It looks like it's around 3.5 or 3.6 on pin 11. Assuming it should be higher? That should be fine I just wanted to make sure you had an AC signal there. That is your clock signal. Quote Link to comment Share on other sites More sharing options...
SignGuy81 Posted June 1, 2017 Share Posted June 1, 2017 Do the same check on pin 39 of the riot chip. Quote Link to comment Share on other sites More sharing options...
New Horizon Posted June 1, 2017 Author Share Posted June 1, 2017 (edited) Do the same check on pin 39 of the riot chip. Hmmm, if I checked the correct pin then it looks to be around 2.6 on pin 39 of the riot chip. Edit: Verified it was the correct pin. So yeah, around 2.6. Guessing it should be 5v? Edited June 1, 2017 by New Horizon Quote Link to comment Share on other sites More sharing options...
New Horizon Posted June 1, 2017 Author Share Posted June 1, 2017 That should be fine I just wanted to make sure you had an AC signal there. That is your clock signal. Ahh, ok. Cool. Quote Link to comment Share on other sites More sharing options...
SignGuy81 Posted June 1, 2017 Share Posted June 1, 2017 Hmmm, if I checked the correct pin then it looks to be around 2.6 on pin 39 of the riot chip. Edit: Verified it was the correct pin. So yeah, around 2.6. Guessing it should be 5v? that sounds about right, now check for the same thing on pin 26 of the TIA Quote Link to comment Share on other sites More sharing options...
New Horizon Posted June 1, 2017 Author Share Posted June 1, 2017 that sounds about right, now check for the same thing on pin 26 of the TIA Around 2.5 / 2.6 on that one. Quote Link to comment Share on other sites More sharing options...
SignGuy81 Posted June 1, 2017 Share Posted June 1, 2017 (edited) Check pin 1 of the 6507 for +5V. May be lower on that pin but see if you have anything. Meter back on DC now Edited June 1, 2017 by SignGuy81 Quote Link to comment Share on other sites More sharing options...
New Horizon Posted June 1, 2017 Author Share Posted June 1, 2017 Check pin 1 of the 6507 for +5V. May be lower on that pin but see if you have anything. Meter back on DC now Looks like the 6507 is getting a hair shy of 3V. Quote Link to comment Share on other sites More sharing options...
SignGuy81 Posted June 1, 2017 Share Posted June 1, 2017 After checking pin 1 of 6507 then check pin 4 for +5V. That one should be right at +5V Quote Link to comment Share on other sites More sharing options...
SignGuy81 Posted June 1, 2017 Share Posted June 1, 2017 Looks like the 6507 is getting a hair shy of 3V. That's fine, there is a resistor between 5V and that line, plus a cap to ground so that line isn't going to be 5V I just wanted to make sure you had something on pin 1 Quote Link to comment Share on other sites More sharing options...
SignGuy81 Posted June 1, 2017 Share Posted June 1, 2017 (edited) Let me know what you have on pin 4 of 6507, back on the DC setting with meter Edited June 1, 2017 by SignGuy81 Quote Link to comment Share on other sites More sharing options...
New Horizon Posted June 1, 2017 Author Share Posted June 1, 2017 (edited) After checking pin 1 of 6507 then check pin 4 for +5V. That one should be right at +5V Yes, indeed. Pin 4 is exactly 5V. Thanks so much for helping. Edited June 1, 2017 by New Horizon Quote Link to comment Share on other sites More sharing options...
SignGuy81 Posted June 1, 2017 Share Posted June 1, 2017 Check pin 34 of the RIOT chip, it should be a lower voltage too at that spot. Quote Link to comment Share on other sites More sharing options...
New Horizon Posted June 1, 2017 Author Share Posted June 1, 2017 Yes, 3V or just shy of it. Quote Link to comment Share on other sites More sharing options...
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