Ransom Posted January 17, 2010 Share Posted January 17, 2010 I started up my 5200 to play some Joust last night, and was disconcerted to see that the platforms were green! I'd adjusted the color pot with the help of the CPS diagnostics cart last year, and the colors had been perfect since. So seeing the amber platforms come out green was a surprise. I was again surprised when, as the machine warmed up, the platforms switched back to amber. I tried a different TV, and a different power supply, and the problem continued. It starts out green, and then within five minutes the colors return to normal. I also tried a different 5200. Same problem! So is this a common problem with 5200s? Or am I just incredibly lucky to have two with exactly the same problem? Most importantly, does anyone know the likely cause of this problem? Quote Link to comment Share on other sites More sharing options...
GroovyBee Posted January 17, 2010 Share Posted January 17, 2010 Most importantly, does anyone know the likely cause of this problem? A change in temperature (as components on the PCB get warmer) is probably the cause. Quote Link to comment Share on other sites More sharing options...
bohoki Posted January 17, 2010 Share Posted January 17, 2010 anybody know why mario brothers colors look all wrong? was it sabotaged by a nintendo loyalist? Quote Link to comment Share on other sites More sharing options...
Ransom Posted January 17, 2010 Author Share Posted January 17, 2010 Most importantly, does anyone know the likely cause of this problem? A change in temperature (as components on the PCB get warmer) is probably the cause. Okay. Which components would be the most likely to cause the problem to occur? Quote Link to comment Share on other sites More sharing options...
GroovyBee Posted January 17, 2010 Share Posted January 17, 2010 Okay. Which components would be the most likely to cause the problem to occur? I'm not familiar with the 5200 hardware but a good start would be the RF section. I'll have a look at the schematic. Quote Link to comment Share on other sites More sharing options...
GroovyBee Posted January 17, 2010 Share Posted January 17, 2010 Just looked at the schematic. Does the problem happen on both channels? Quote Link to comment Share on other sites More sharing options...
Ransom Posted January 17, 2010 Author Share Posted January 17, 2010 Just looked at the schematic. Does the problem happen on both channels? I just checked -- yes, it does happen on both channels. Perhaps unrelated to that, but the channel select switch seems loose (it's easy to wiggle from the board) and pushing it gives a lot of static on the TV. And you have to push it back and forth a few times to get it to come in on channel 2 (I normally use channel 3). Regardless, the problem does exhibit on both channels. Quote Link to comment Share on other sites More sharing options...
GroovyBee Posted January 17, 2010 Share Posted January 17, 2010 The colour delay is controlled by pin 17 of the GTIA (CO14805-03). It could be that the track on the 600K variable resistor is causing problems or the .01 (uF?) capacitor connected between pin 17 and ground. I've no idea what case style the variable resistor is but try replacing it and the capacitor as a first attempt. If that doesn't work then try replacing the 10 pF? capacitor between pin 21 of the GTIA and the 3300 ohm resistor. If that doesn't work try replacing the 2N3904 transistor. If that fails I'm outta ideas . Quote Link to comment Share on other sites More sharing options...
Ransom Posted January 17, 2010 Author Share Posted January 17, 2010 Thank you very much for your help, GroovyBee! I'll give it a shot when I can get the parts. Quote Link to comment Share on other sites More sharing options...
GroovyBee Posted January 17, 2010 Share Posted January 17, 2010 As a sanity check make sure that the values/part numbers of the components on the schematic are the same as those found on the PCB. If they differ use the component values found on the PCB. The components tolerances should be the same or lower too. The only exception to that is the voltage rating on any caps that need replacing (if specified). You can use a higher voltage rating than the ones on the PCB without any problems. Quote Link to comment Share on other sites More sharing options...
Ransom Posted January 18, 2010 Author Share Posted January 18, 2010 Good advice. Will do! Quote Link to comment Share on other sites More sharing options...
Prodos8 Posted January 18, 2010 Share Posted January 18, 2010 My s-video modded 5200 does the same thing on Joust. When the unit is cold the game starts up with green hues on platforms which change to browns/amber as the unit warms up. I figure its normal and as the parts warm the colors shift a bit. If you need to adjust the color pot you should do it after the unit warms up. Quote Link to comment Share on other sites More sharing options...
Ransom Posted January 18, 2010 Author Share Posted January 18, 2010 Hmm. That's interesting, Prodos8. Especially because BOTH of the motherboards I own have this same problem. Maybe it's some kind of wacky problem built into the system? Because it's not just Joust, of course. That's just the game it's easiest to notice it on. The hair of the guy in Gremlins also goes from green to brown. Or brown to red, depending on how your color pot's set. It also works on other games...as well as the CPS Diagnostics Cartridge's Colorbars screen. Turn the unit on, adjust the pot so the colors above and below the grey line are the same. Wait five minutes, and the one above the bar will have shifted from a yellowish color to an orangish color. Adjust again, turn it off, turn it back on, and you'll be back where you started. I'm going to post a question/poll and see if this really is normal, or if it's just a common failure point. Thank you very, very much for posting your experience, Prodos8!! Quote Link to comment Share on other sites More sharing options...
GroovyBee Posted January 18, 2010 Share Posted January 18, 2010 If an AV modded console does it then its the components around GTIA that are the problem and not the RF. Quote Link to comment Share on other sites More sharing options...
Ransom Posted January 18, 2010 Author Share Posted January 18, 2010 If an AV modded console does it then its the components around GTIA that are the problem and not the RF. Definitely. I've looked at the field service manual and listed out the possible problem components. For example, it'll say that C11 is "Cap, Ceramic, Axial, 10pF, 50V" but when I go to buy one, I have a choice of tolerances. Is there any way for me to know what tolerance to get, or should I play it safe and get the tightest tolerance I can? (I wish I had an oscilloscope so I could figure out exactly which part is "warming up", but I don't...and I can't afford one, based on the prices I've seen. The Atari Field Service Guide assumes you have one, and gives the peak-to-peak values to look for. So I've just listed out all the parts they have for possible replacement under the "color problems" section.) Quote Link to comment Share on other sites More sharing options...
GroovyBee Posted January 18, 2010 Share Posted January 18, 2010 Thinking about it some more it probably not the colour adjustment pot that is the problem if more than one person's machine does it. What is the tolerance of the capacitors I mentioned earlier? You'll have to look on the PCB because the schematic doesn't say. I'd assume they are quite large otherwise a colour adjustment pot probably wouldn't be needed. Quote Link to comment Share on other sites More sharing options...
+Mitch Posted January 18, 2010 Share Posted January 18, 2010 I had a similar problem on one of my 2600s and it was the voltage regulator starting to die. Mitch Quote Link to comment Share on other sites More sharing options...
Ransom Posted January 18, 2010 Author Share Posted January 18, 2010 I had a similar problem on one of my 2600s and it was the voltage regulator starting to die. Mitch Hmm. Well, at least that should be something I could test with a multimeter. I'm thumbing through the 5200 field service manual, but if anyone knows where to test and what I'm looking for, let me know! Quote Link to comment Share on other sites More sharing options...
Ransom Posted January 19, 2010 Author Share Posted January 19, 2010 According to Brad @ BEST Electronics, the color change during warm-up is actually normal for 5200s! Quote Link to comment Share on other sites More sharing options...
Greg2600 Posted February 11, 2010 Share Posted February 11, 2010 I was playing my 5200 yesterday, flipping through roms on the USB cart, and noticed that many of the games were very dark, with mostly browns and reds. When compared with an emulator on my pc running at the same time. I guess I never really tried to notice it before. How long does the 5200 need to "warm up?" Quote Link to comment Share on other sites More sharing options...
Ransom Posted February 12, 2010 Author Share Posted February 12, 2010 I have two, 2-port motherboards. One needs about five minutes, the other needs about 10. In either case, you can see the colors slowly change over time. It's not on/off...it just sort of goes from one shade to another, gradually. Joust starts out with green platforms, then the green becomes more and more yellow, until eventually they're a nice amber color like they're supposed to be. I'm always leery of comparing to emulators, though, because often the color palettes in them are a little off. Plus sending a signal to a TV (especially RF) is a lot different than what happens in an emulator. Plus TVs themselves have lots of settings and variations. So I just try to find the best setting I can for the situation (preferably using a color test pattern when available). Quote Link to comment Share on other sites More sharing options...
Divya16 Posted February 12, 2010 Share Posted February 12, 2010 I was playing my 5200 yesterday, flipping through roms on the USB cart, and noticed that many of the games were very dark, with mostly browns and reds. When compared with an emulator on my pc running at the same time. I guess I never really tried to notice it before. How long does the 5200 need to "warm up?" It takes about 558 ns to warm up in my case (on real machine). I haven't noticed any issues but I'm not using any USB cart. Quote Link to comment Share on other sites More sharing options...
Greg2600 Posted February 22, 2010 Share Posted February 22, 2010 I've left mine on for an hour, no change. For me, seems like blues are showing up purple, such as miner 2049er here: Then here's Castle Crisis where the greens are yellow: Quote Link to comment Share on other sites More sharing options...
Ransom Posted February 22, 2010 Author Share Posted February 22, 2010 Have you tried adjusting the color pot? Quote Link to comment Share on other sites More sharing options...
Greg2600 Posted February 23, 2010 Share Posted February 23, 2010 (edited) Ah, forgot about that POT. Yeah, got it pretty good now. The picture itself, color wise, is still a lot darker than on an emulator. Any way to adjust that, or was that just the system? Edited February 23, 2010 by Greg2600 Quote Link to comment Share on other sites More sharing options...
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