rednakes1 Posted October 17, 2016 Share Posted October 17, 2016 (edited) Okay, so I just tried it on my Rev 13 four-switch woody 2600. Huge difference! Attached is a grid of photos, with the 'Before mod' on the left, and the post-mod on the right. I've also attached a clear photo of the 820 Ohm resistor I soldered on. Thanks for sharing this mod. Next I will work on an AV mod because the RF is very fuzzy. Edited October 17, 2016 by rednakes1 3 Quote Link to comment Share on other sites More sharing options...
ubersaurus Posted November 6, 2016 Share Posted November 6, 2016 I think this is exactly what mine needs - I've noticed the color is off from my Jr, and those photos show the exact colors I see on Pac Man, for example. 1 Quote Link to comment Share on other sites More sharing options...
Level42 Posted November 6, 2016 Share Posted November 6, 2016 (edited) Yes my 4-switch Sunnyvale with Rev.13 PCB must be missing this resistor too as the colors (despite turning them up to the maximum on my TV) are still not full enough. Gotta find my resistors.... Edited November 6, 2016 by Level42 Quote Link to comment Share on other sites More sharing options...
Level42 Posted November 6, 2016 Share Posted November 6, 2016 Okay, so I just tried it on my Rev 13 four-switch woody 2600. Huge difference! Attached is a grid of photos, with the 'Before mod' on the left, and the post-mod on the right. I've also attached a clear photo of the 820 Ohm resistor I soldered on. Thanks for sharing this mod. Next I will work on an AV mod because the RF is very fuzzy. You did a very neat job installing that resistor. The isolation tape is not really needed, there is an insulating lacquer layer over the PCB.....but it won't hurt of course Quote Link to comment Share on other sites More sharing options...
rednakes1 Posted November 6, 2016 Share Posted November 6, 2016 Thanks for the tip, yeah I eventually removed the tape and it didn't do any harm. One thing I noticed with the video quality is that you may see a row of white dots on the left side of the screen. My 2600 Jr. also has the same effect so I guess it's a symptom of the extra saturation. 1 Quote Link to comment Share on other sites More sharing options...
Level42 Posted November 7, 2016 Share Posted November 7, 2016 Mmmm, doing the mod now....your pic really helps (saves counting pins ) Quote Link to comment Share on other sites More sharing options...
Level42 Posted November 7, 2016 Share Posted November 7, 2016 WOW !!!! What a difference one little resistor can make !!! Finally the Demons of Demon Attack look like I remember them (well, I mean almost like I remember them, I am in PAL territory so I grew up with the (less colorful) PAL 2600 and games, but anyway, the colors are much much richer now ! Excellent tip Pretty weird is this is _so_ old and must be well known since it was an official Atari bulletin. Quote Link to comment Share on other sites More sharing options...
Keatah Posted November 7, 2016 Share Posted November 7, 2016 Can someone post a pic of Video Pinball running on a modded machine? Quote Link to comment Share on other sites More sharing options...
ubersaurus Posted March 12, 2017 Share Posted March 12, 2017 I've got kinda funky colors on a revision 17 board that had the resistor added on. I don't know if that revision needs it or not, but yeah - some colors are blurry and indistinct, everything is kind of washed out, some colors aren't easily distinguished (like Pitfall Harry's shirt and the background). Anyone know if I should try removing it or not? Quote Link to comment Share on other sites More sharing options...
mojoatomic Posted March 13, 2017 Share Posted March 13, 2017 Yes, remove it - the resistance had been doubled on the board as it already has the resistor from the factory. 1 Quote Link to comment Share on other sites More sharing options...
ubersaurus Posted March 13, 2017 Share Posted March 13, 2017 Well that is the other thing - there was no resistor already on the underside of the TIA when this was attached. So you're saying that the one designed for the system is already elsewhere on the board? Quote Link to comment Share on other sites More sharing options...
mojoatomic Posted March 13, 2017 Share Posted March 13, 2017 Yes, look at the topside of the board and find R234 1 Quote Link to comment Share on other sites More sharing options...
ubersaurus Posted March 13, 2017 Share Posted March 13, 2017 Cool - I'll give that try tonight. I had my suspicions, but figured I'd check with folks who may know for sure. Thanks! Quote Link to comment Share on other sites More sharing options...
mojoatomic Posted March 13, 2017 Share Posted March 13, 2017 Cool - I'll give that try tonight. I had my suspicions, but figured I'd check with folks who may know for sure. Thanks! Don't remove R234, just the resistor that was added to the reverse side of the board - Quote Link to comment Share on other sites More sharing options...
ubersaurus Posted March 14, 2017 Share Posted March 14, 2017 That definitely fixed the color issue. Now if only I could suss out why certain colors seem so fuzzy and indistinct on certain backgrounds (like the blue ghost in Ms. Pac-Man, or Pitfall Harry's shirt), this rev 17 board would be in business. Quote Link to comment Share on other sites More sharing options...
Kapikui Posted March 20, 2017 Share Posted March 20, 2017 Is this something for the RF output only, or does it work for the composite mods as well? Quote Link to comment Share on other sites More sharing options...
Hank Rearden Posted March 20, 2017 Share Posted March 20, 2017 Is this something for the RF output only, or does it work for the composite mods as well? I've been wonder this same thing myself. Quote Link to comment Share on other sites More sharing options...
+DrVenkman Posted March 21, 2017 Author Share Posted March 21, 2017 I've been wonder this same thing myself. I haven't dug into the schematics but it should work for all video output. With this little tweak, you're literally modding right at the source of the video signal for the entire system, as it leaves the TIA chip. Quote Link to comment Share on other sites More sharing options...
RamrodHare Posted June 5, 2017 Share Posted June 5, 2017 I've been wondering about this ever since I got my revision 12 board back in a case. It doesn't have the resistor, but from what I've read, it will help the color if I add one, right? Also, while I've got the case opened up again, should I go ahead and replace the caps and voltage regulator? I'm guessing it needs something, since the color is off a bit when compared to my 7800, which is a lot more vibrant and bright. Quote Link to comment Share on other sites More sharing options...
Andromeda Stardust Posted June 5, 2017 Share Posted June 5, 2017 You guys have me curious. I'm gonna go take another crack at my morning woody. Nope. Mine is a revision 12. No resistor underneath the TIA. Picture is good enough. I'm just gonna leave it stock for now. FYI, I performed the 820ohm resistor mod sometime last year '15 or '16, can't remember, but it was fall. i do not regret it. Makes the colors pop! 1 Quote Link to comment Share on other sites More sharing options...
H454 Posted June 5, 2017 Share Posted June 5, 2017 I've been wondering about this ever since I got my revision 12 board back in a case. It doesn't have the resistor, but from what I've read, it will help the color if I add one, right? Also, while I've got the case opened up again, should I go ahead and replace the caps and voltage regulator? I'm guessing it needs something, since the color is off a bit when compared to my 7800, which is a lot more vibrant and bright. Console5's caps kit includes the 820 resistor and the joystick protection update to keep from wreaking the 4050ic. From console5 site: " Service Update Parts: These updates were included in field service campaigns. Note that depending on revision, not all parts may be necessary for all 2600 models. Pre-Revision 14: A pair of zener diodes and capacitors used for static protection on the trigger lines (J202 & J203). Equivalent to service parts CA018263.Each small yellow .1uf cap is soldered across each zener diode. Each diode/cap combo is then soldered with the diode's stripe end connected to joystick port Pin 6 and the opposite side to the nearest ground plane. Pre-Revision 16: An 820 ohm resistor added as a field service repair across TIA pins 6 and 9 and only incorporated in late-model PCBs. Improves color saturation. Pre-Revision 14 consoles use a 4050 IC which can go bad and cause joystick button problems. Most 2600 PCBs do not have the 4050 and we've chosen to make it available separately for cost savings. The zener/cap parts provided are intended to limit the static issues which cause 4050 failure. Additional service information available on our wiki page" 1 Quote Link to comment Share on other sites More sharing options...
RamrodHare Posted June 5, 2017 Share Posted June 5, 2017 Console5's caps kit Thanks for the link! Quote Link to comment Share on other sites More sharing options...
H454 Posted June 5, 2017 Share Posted June 5, 2017 Thanks for the link! No problem. I've put the resistors on a couple early boards and does improve the color - well worth the 30 seconds to install. Quote Link to comment Share on other sites More sharing options...
RamrodHare Posted June 5, 2017 Share Posted June 5, 2017 No problem. I've put the resistors on a couple early boards and does improve the color - well worth the 30 seconds to install. I just ordered the kit. I'm looking forward to seeing the difference the resistor makes. Whats odd is that on my HDTVs, the color is really close on the 2600 and the 7800. Where it really stands out is on the CRTs. As an example, Seaquest on the 7800 connected to my 13 inch CRT, Game mode off, brightness at lowest setting, everything looks great. Now the 2600, I have to turn game mode on and turn the brightness up past halfway to get a similar picture. So if the resistor corrects that so I don't have to adjust the settings on the TV all the time, I'll be a happy camper! Quote Link to comment Share on other sites More sharing options...
atari-dna Posted June 5, 2017 Share Posted June 5, 2017 I've installed the resistor once, it seemed to help. The "mini" version of the resistor (which has the same characteristics as an older, physically larger resistor) fits nicely. About 10 of these for a dollar at DigiKey. I have a part number if anyone is interested. Sent from my iPhone using Tapatalk Quote Link to comment Share on other sites More sharing options...
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