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As there can be some confusion on how to install the UAV into a 4-switch NTSC 2600 console due to the variants that exist, I thought I would try and collate all of the basic information needed for installing the UAV into these model 2600s. While the different revisions do have some slight changes between them, in all cases the area where to get the signals needed for the UAV to work are located in the same basic locations. This is is not a comprehensive guide but more of a quick reference for those that already know how to open up the 2600 and are semi familiar with the layout inside of the 4-switch NTSC consoles. UAV (Ultimate Atari Video) Layout:- The UAV has basically remained the same on its design and layout since around 2017 when the current revision D was released. I only use the basic UAV board in all of my installs as I find that easier to wire to and provides me in more flexibility overall. Below is a diagram showing you the spots on the UAV you need to be concerned with on NTSC 2600 Installations. In all installs, the UAV will need to have power, ground, color signal, and a few other video signals provided to it for it to function properly. Take NOTE that you attach the signal wires for S, 1, 2, & 3 along the center and smaller vias on the UAV. If you have a pre-built UAV with a header block soldered here, just solder wiring to the tops of the header pins to make it easier. Different revisions:- The 4-switch NTSC consoles come in revisions starting with rev12 and ending up with rev17 that I've seen personally. Meaning there are variants in between but the good news is that there are really only about 3 different layouts for the components between all of these revisions in the area that we are concerned with for the UAV. Look around the top of the main board to see which Revision of the board you have so that you know which of the sections below to refer to for your UAV install. Power, Ground and Audio:- All revisions of the 4-switch NTSC consoles share the same points for power, ground, and audio that can be used for UAV installations. While the top board trace layouts look different in the areas below and the location of the RF output RCA jack is in different spots, the actual points are the same and in the same locations. I've provided pictures that show how this area is on the Rev 12 - 14 and Rev 16 & 17 models below. Revision 12 & 13 NTSC TIA signal locations for UAV:- The revision 12 and 13 NTSC consoles is pretty straightforward as the signals are all in a line from the main resistor section just to the right of the TIA chip. The signal points on the UAV for S, 1, 2, 3, & Co In are shown below. Revision 14 NTSC TIA signal locations for UAV:- The revision 14 NTSC console layout is similar to the earlier revisions with the only change being where you grab the signal for connection 2 to the UAV. The signal points on the UAV for S, 1, 2, 3, and Co In are shown below. Revision 16 - 17 NTSC TIA signal locations for UAV:- The revision 16 & 17 NTSC consoles have their signals in the same location as the Rev14 show above, with the one change being an extra 820Ω resistor that was added to the board layout that has to be disconnected from the circuit. This resistor is located directly right of the TIA and is marked as R234, although you cannot see the silkscreen indicating this until you lift the resistor out of place. If you do not disable this resistor, you will end up with incorrect color hues on all colors from the UAV that cannot be adjusted out with the color trimmer. You can either clip the leg of the resistor, de-solder it, or remove the resistor completely. The signal points on the UAV for S, 1, 2, 3, and Co In are shown in the picture below. The picture shows an alternate location for the S signal, but you can also get it from the same location as the Rev 14 in most cases. UAV output colors appear horribly off kilter? As mentioned in the Rev 16 & 17 section, there is an extra resistor on the main board that has to be disabled. While this resistor doesn't have a dedicated location on the earlier revision 4-switch NTSC consoles, it was sometimes added from the factory and therefore bodged into place. Look the presence of this resistor either on the bottom of the main board attached to pins 6 and 9 of the TIA chip, or possibly soldered on the top component side next to the TIA socket. In these cases, it is easiest to just clip the resistor on one leg to disable it without fully removing it. You might want to add shrink tubing or some other way to insulate the lifted/cut leg of the resistor so it can't short against anything. UAV output wiring:- The output side of the UAV is along the same point that you attached the TIA color signal wire to. All of your output signal jacks will require a connection for the signal output and also ground. What I usually do in my installs is to run a shared ground wire for both audio and composite video from the ground pin near the composite output on the UAV. I then run another second shared ground for the chroma and luma outputs for s-video using the ground pin between Co In and chroma out on the UAV outputs. The diagram below shows the S-video connections on the female s-video as viewed from the front of the s-video jack. What about that blue box thing on the UAV, what is that for? :- The blue box near the output side on the UAV is a trimmer adjustment for changing the way color artifacting looks through composite output. However, this trimmer has no impact when used on the 2600 console as it was mainly put into place for using the UAV on the Atari 8-bit computers where more games used NTSC artifacting.
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Hi Everyone: I previously posted in this thread, but it was suggested we break this out to its own thread for folks with similar hardware and issues to reference going forward. Back in April 2017 I purchased an NTSC composite-modded Woody 4-switch CX2600A from @Osgeld. It had been working great but was in storage for the past year unused (climate-controlled, dry finished basement in closed Rubbermaid storage container). I recently pulled it out after purchasing a Harmony cart for it, and when I hooked it back up it was not displaying color, only black and white. The black and white switch still works, as evidenced when playing Adventure and switching it I can see the grayscale changing. Here's a picture of the composite mod, which Osgeld mentioned in the previous thread: In the other thread, it was suggested I clean out and adjust the R213 pot which affects color. I used some electrical contact cleaner and adjusted it back and forth to free up any corrosion, but it did not fix the issue. I know it's getting voltage as I measured it, which I'll reference below. I also noted I can see some convergence going on when adjusting it either way, so it seems to be working as intended. The good folks in the previous thread asked me to take some voltage measurements of the areas of the board responsible for the color signal, which I've copied here: R213 - 6.22 R212 left side - 9.52 R212 right side - 6.23 TIA pins 9 and 20 - 5.02 TIA pin 10 - 4.66 I put in Asteroids, and yes voltage on pin 9 changed to 2.75. Turning the pot clockwise about a quarter turn increases voltage slightly to 2.82. Counter clockwise a half turn and it goes down to 1.81. For Pin 10, turning the pot clockwise about a quarter turn increases to 5.95. Counter clockwise a half turn and it goes down to 0.35. I was also asked to measure the voltage along the traces for multiple resistors. For orientation, please reference the picture below: ^ Top; v Bottom C210 "bottom" - 4.78 C210 "top" - 5.02 R210 "bottom" - 4.98 R210 "top" - 5.01 C211 "bottom" - 0.19 <- I wonder if this could be the problem? C211 "top" - 4.98 R222 "bottom" - 0.19 R222 "top" - 0.00 C215 "bottom" - 0.19 C215 "top" - 0.00 Upon close inspection, C211 doesn't look to be a stock resistor (maybe part of the mod performed?) and might suffer from a cold solder joint as referenced by a poster in the other thread: Or maybe those voltage readings are completely normal...I dunno. Here are some other pictures of the circuit board and mod for reference: The good folks @ChildOfCv, @DrVenkman, @fdr4prez and @-^CrossBow^- helped me get to where I am now, but I need some help to further diagnose this issue and identify a fix. Also, as I mentioned, this will be a good reference in the future for others with this mod setup. TIA!
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I used a couple of the cheap AV mods a while back on my 2600 Vader and my 7800. The mod worked out great on the 7800. The picture is very clear and there is no color bleeding. On my Vader (4-switch, revision 12 board), the picture is, well, terrible. There is quite a bit of color bleeding and it makes most of the text or scores, unreadable and some games are so much of a mess that they hurt my eyes. I recently bought a 2600 Jr. that I intended to use the RF on, since the picture is fine. The issue is, I'm running into a lot of compatibility issues with different TVs. I bought the Jr. because I wanted an Atari that was easier to transport to friends homes and such, but a lot of new TVs just won't work with the RF signal and carrying a VCR around is worse than just carrying my 7800. Now here's what I'm wondering.. Isn't the Jr similar to the 7800, as far as how the video output is handled? If so, shouldn't the cheap mod work just as well on it as id does on my 7800? I know that the 7800 uses a 4050 chip and I'm guessing that has something to do with the cheap AV mod working and the Jr. has the same chip, right? I also know that the Vader doesn't have this chip and the cheap mod doesn't work as well. So..... (I hope I'm making sense and not just rambling. ) If I'm right, I'm thinking about pulling the mod board from the 4-switcher and using it in the Jr. Then buying a mod kit that is better suited for the 4-switcher. If my thinking is correct and the cheap mod will work fine on the Jr, What mod should I install in the Vader/4-switcher? I have heard nothing but good reviews on the UAV mod and it's the only one that people have been talking about lately. I also read a post from a few years ago about a mod that uses the 4050 chip, but the circuit was really complicated to build and I'm not the best at soldering.. So, what's the recommendation?
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The video from my woody 4-switcher jumps around rapidly on the TV screen, and I'm hoping someone will have suggestions on how to fix this. To get a feel for the problem, see the attached pictures and , which capture a few of the positions the screen is jumping between. I'm using a little adapter to send the video and sound into the coax input of my TV. ---The problem exists with any of the ~10 games that I tried. ---When Defender is first turned on, the screen is stationary for a second before any ships appear on the screen. As soon as the ships appear, the video starts to jump around and the jittering never stops. ---The problem exists on both of the modern TVs I've tried. ---Inserting an RF filter at the coax input of the TV makes no difference. ---Replacing the original RCA cable from the Atari 2600 with a modern RCA cable makes no difference. ---Rescanning channels on the TV does not solve the problem. ---Turning the color adjustment knob adjusts the colors but does not solve the problem. ---The main big (blue in my case) capacitor seems to still be ok: it's measure capacitance is about 2400 microfarads. ---The green chicklet capacitor has a capacitance of about 0.4 microfarads, which is surprisingly a little high but maybe that's ok? The green chicklet capacitor and the voltage regulator (both in the lower left of the attached image ) are often blamed for fuzzy/snowy video issues but not (as far as I know) for the jittering video I am seeing. Does anyone have a guess as to the most likely culprit, or how I might use a multimeter to check the voltage regulator? Thank you in advance for any advice you can offer!
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