2600 Chewnyor Fixit & Mod kit - pt. 3
Entry posted by Nathan Strum in 2600 repair
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Time to cut stuff up! Choppity-chop!
And yes... this part is non-reversible. But the cables have to exit the Jr. somewhere. There aren't many places to do this, unless you repurpose the RF jack, or remove the RF modulator and the channel 2-3 switch. Neither is happening here, so I need to cut a hole. Because of how I routed the cables and the location of the mods, I decided the space between the channel 2-3 switch and the corner post of the case was the best spot.
So I measured the width of the cables (stacked vertically) and notched the plastic with an X-Acto razor saw:
I measured the height of the cables, then cut three slots, to minimize the chance of cracking the plastic when I broke the pieces out with pliers: 
Test fitting the cables - the bottom cable lies on top of the circuit board, so the top of the case will need to be notched out to accommodate the height:
A little more cutting and filing, and the Jr. has a new hole:
And the cables fit neatly through:
While I'm working on the case, one of the plastic tabs that holds the circuit board in place had broken off. Here's the intact one:
And the broken-off one:
I used some painter's tape to align it...
And globbed some J-B Weld in there to repair and reinforce it, adding more tape to hold it in place while it cured:
More test-fitting. It all fits - I just need to trim the output wires to length, and solder them to the mods:
Just making sure the case still closes...
More soldering! Solder one, clip the next one to it. Rinse and repeat. I trimmed the excess off afterwards. And yes, I remembered to install a smaller tip in my soldering iron this time. Thanks for asking!
Many (Radio Shack Helping) Hands make light work. Or in this case, re-soldering the +5v and ground wires to the UAV board. You might be able to tell in the photos above, I had soldered them so they came off the edge of the board and ran headlong into the RF modulator. I didn't like that, so I desoldered them and reattached them so they went off to the sides:
With everything finally connected... would it work? Well, rather anti-climactically - yes! First try!
While testing, to avoid shorts, I used some leftover wire to tie some unshrunk heat-shrink tubing to the underside of the the mod boards as insulators. More on that in a minute. I still need to do something about that LED though. Once the case lid goes on, it's almost too dim to see.
While adjusting the colors and checking the S-Video picture quality, I noticed some odd thin black vertical line running down the center of the screen:
Adjusting the trimmer on the UAV mod made it go away:
Remember the parrot from part 1? Here it is, now in all of its S-Video glory (ignore the moiré patterns - it's my camera, not the video): 
So - time to button this all up! But how am I going to attach the mods? Tape? Glue? J-B Weld? Screws? Chewed-up bubble gum? Nope. Wire! I took some leftover solid Cat5 wire, and soldered the ends to a couple of empty vias on the main board:
I put some heat shrink tubing on it for a little extra cushioning, and used it to tie the two boards in place. I left the large pieces of heat-shrink tubing underneath them from before. This anchors them in place nicely, and protects everything from shorting. No glue, no tape, and completely reversible. The black wire to the left is ground for the UAV mod and the audio board.
And finally, the finished mod install. Or more colloquially, ten pounds of crap in a five-pound bag:
And yes - the repaired clip held up just fine:
All buttoned-up with its pigtail S-Video, composite video and audio cables:
Pictures! RF is quite saturated, but looks okay. Although see if you can figure out what's different with these RF pics, from the ones from part 1:
Composite video. Looks good... but is definitely less saturated:
And S-Video. I just couldn't get my camera to reliably capture both interlaced frames. I need to figure that out. But this all looks fine in real life:
RF again. Very saturated, and the color difference between the upper and lower half is far more pronounced than with composite or S-Video:
But since this will be mostly used for composite, I calibrated the color for that:
And S-Video is pretty-much the same. But the text is crisper:
Again, the RF is very saturated. And pretty dark:
And composite is... uh... hey! Those vertical lines are back!
And in S-Video, too! But I didn't change anything. What's going on?
Sometime later... without changing anything, they were almost gone again:
After going back to part 1 and looking at the RF pic there, it's pretty clear those lines were always there. This isn't a mod artifact, it's a Jr. one:
Did you catch the difference in RF pics?
Part 1 used channel 3. Part 3 used channel 2. You can just see the channel number on the tuner on top of the monitor in a couple of photos. For some reason, while shooting the pics for part 3, I was picking up a ton of interference on channel 3. Channel 2 was fine. But this was with a stock Atari RF cable, so I'm not too surprised.
And yes - I did replace that super-dim power LED. Sourcing it was easy - when I replaced the one in John's 7800, I had 99 leftover. 
It's silly, but it's cheaper to buy 100 LEDs off Amazon with free shipping, than to buy one off Mouser and pay for shipping.
I miss Radio Shack.
So that concludes fixing and modding this Jr. It's a far cry from the gross, crud-encrusted mess that I started with:
Even the mangled Reset switch looks pretty-good now:
One thing I overlooked in Part 1 is that the Select and Reset switches are "hinged" at the top (you can see the plastic tabs that serve as hinges in some of the photos there). This is why the entire lower third of the switch has PUSH on it. If you push there, the switches work effortlessly. If you push higher up, there's more resistance and the switches don't respond. I'm sure Atari saved a whopping penny or two by not using actual momentary switches there.
A couple of final shots of the finished product:
Some final thoughts on the Jr. UAV installation: the more I work with the UAV, the more I wish there was a better solution. This took a fair amount of time and figuring out in order to install it. The documentation is really lacking. The need for a separate audio board is clunky. And I'm not sure the results are all that great. The picture is clean, but it still seems quite undersaturated to me, and I don't see any way to adjust it. I miss the CyberTech S-Video mod, but I think it would've been too tall to fit under the Jr's RF shield anyway. Now, if you didn't click on every single link in Part 2 (and why wouldn't you?), you might have missed thread about the CleanComp Composite Mod, currently under development. I only came across that thread a few days ago, and the Jr. was already finished by then (it takes awhile to write up these blog entries), but that mod looks very promising indeed. There are a lot of tech-savvy eyes on that thread, giving insight and feedback, and this could end up being the best (and most straightforward) 2600 mod yet once it finally gets sorted. It's making me reconsider using a UAV in any of my own consoles. 
Up next: the final chapter in the saga of "Adding a bunch of UAV mods to John's consoles" as I install one in... a four-switch woody!
And this time, I'm drilling holes.
Lots, and lots of holes.
Published 2/25/23 12:30PM
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