A bad 2600 composite mod, or just a bad 2600?

[Akito01]

So, I got my 2600jr from eBay today. Bad sign - it had already been opened, since three of the plastic screw posts were broken, meaning that only two screws were keeping the case closed. In addition, all three of the metal shielding pieces were missing. Still, nothing seemed amiss as far as the board itself was concerned, so I went ahead with the most basic composite video mod (at the moment, I have no way to connect via RF).

Everything went fine with the wires and the soldering and everything, so I put the case back together, put in a copy of Space Invaders (my only cart at the moment), and turned it on. This was the result:



I find it hard to think that it is a failure of the video mod, because in that case I'd either have no picture at all, or just a very dark picture as is often reported with this very basic mod. Without the cartridge inserted, I either get a black screen or a black and white version of this pattern (the color/BW switch itself seems to have no effect either way).

Is this a hopeless case? What could cause this kind of failure? Should I just extract the cartridge slot as I originally intended for the Flashback 2 mod, or is there something I else I can do or test for in order to see if I can get this 2600jr working properly? It isn't likely to be a bad cartridge, is it?

[Ed Oscuro]

You should've returned it immediately on sign of tampering. Was it working when you got it? That should have been your first step...now that you've messed with it, your chances of a refund may have gone out the window as the seller may plausibly claim you broke it / made it worse.

[Akito01]

You should've returned it immediately on sign of tampering. Was it working when you got it? That should have been your first step...now that you've messed with it, your chances of a refund may have gone out the window as the seller may plausibly claim you broke it / made it worse.

It was sold as-is, with no guarantee that the machine was working. At the time I ordered it, I didn't care, because I was just looking for a cartridge slot. If I'd educated myself a bit more ahead of time, I'd have spent a bit more money to ensure that I did get a guaranteed working machine. Lesson learned, certainly, but I was curious for any feedback.

[Ed Oscuro]

As-is is always a surefire way to get scrap, unfortunately. It's a rare honest person who will describe something as broken. If you were in the business of repairing these it might have been worthwhile, maybe. It may still be possible to fix it, ask around; if you're lucky the part that's done is something you can find a replacement for (maybe a microcontroller, though I doubt that's the cause, or maybe a RAM or it could even be something simple like a broke trace or whatever).

[Pantechnicon]

It could also be a dirty cartridge or cartridge port. I've seen that sort of pattern before when dealing with less-than-clean equipment. I'd consider cleaning both the cartridge connector and your cart with some sort of electronic solvent or degreaser.

It's too bad you only have one cart to test this with, as the problem could be strictly therein.

[Akito01]

Well, I've checked both the cartridge pins and the slot, and they both look pretty good.

Looking closely at the board again, I noticed that the resister at C3 has been damaged and severed, and the capacitor (?) at C6 is missing, with the stump of one leg still poking out slightly. Something bad obviously happened to this board at one point -well, not so obviously, because I didn't notice anything amiss originally. I don' t have enough experience to know what I'm looking for, but once I started giving this thing a really close inspection, I noticed those two issues. Before I start ripping out the cartridge slot, is it worth it to try and replace those parts at C3 and C6, or is it unlikely that those parts are actually to blame and the problem may be elsewhere?

[Akito01]

Because I suck so much at soldering, I didn't really want to have to stick wires to the chip pins and so forth, but the original composite mod with the single jumper wire produced a picture that was far too dark and fuzzy to be useful. In any case, I'd already had the extra bits I'd need for the Ben Heck mod, and I went ahead with it. I still have to find a way to mount or encase the extra bits, but the thing actually works. The picture is not at all sharp, but it is bright and clear enough to be playable. I don't know if I trust myself to do a more complicated mod for a better picture. Still, it looks pretty OK, and given how badly I could have mucked this up, I'm pretty happy with the end result.

[MASTERWEEDO]

so why did it show up as a white mess at first?

[Akito01]

so why did it show up as a white mess at first?

That was the eBay 2600. This 2600 is one I ordered from The Goat Store (I guess I did leave that part of the story out). I still have the eBay 2600, which I'm debating about stripping out the cartridge slot and doing the Flashback 2 mod, since the video output on the FB2 is a lot sharper, but I don't have a lot of confidence to be able to cleanly solder all those wires. Right now, I'm just thinking of the best way to mount the PCB and RCA jacks on the modded 2600.