Rastamafugg

? Thankfully, no. DC for both. The little I know about electronics encompasses that at least ?

Well, that makes sense. My MC-10 is an AC powered machine. It mostly works fine, though, with a DC power supply (It just needs minus voltage to operate the serial port). I've been testing both with the same wall wart and got confused. ?

And after I read your whole message, ? I'll post some pictures of the pins and test continuity from there to the rest of the system. I cleaned them and they appeared to be in good condition on an earlier inspection, but I'll give them another go over.

Well, I never claimed to be an electronics expert, thankfully! ? I was troubleshooting an issue with my MC-10 earlier this week involving its rectifier, and the rectifier was a three-pronged item that, to my ignorant eye, looked like the part on the 7800 I tested. ? Now I have to go find the rectifier!

Ok, got some time to test voltages. The reading across the big cap seems to be stable at ~8.95v under load with a 2600 cart inserted. I got strange readings from the outer pins of the rectifier, though. Mostly under 1v on both sides. If the rectifier is working properly, what should the values be?

Here is my serial number from an A1 with expansion port:

Thanks for the detail! I'll try to get some voltage measurements and update here. And I ordered a logic probe, so I should be able to do a little more in-depth debugging this weekend.

@-^CrossBow^- I did take a card with some ipa-wet paper and put it into the slot and used Q-tips to clean the visible parts of the pins. Not much room to get deep into the extra 7800 pin at the edges, so it might still be a corrosion issue, I suppose. Although I tried a few cartridges last night and when I put a 7800 cart in, it would stop powering on at all (even after going back to a known working 2600 cart), which means something is shorting out, doesn't it? I tried again this morning to similar results, so maybe reconnecting that cap is causing the short. Wish I had an oscilloscope, or even a logic probe, I suppose. All I have is a multimeter for testing.

I was able to get one 7800 game to play long enough for a short game, and I think I got another to display the rainbow loader, but then it went to black screen. Everything else has been black screen. I do have a DragonFly, although I haven't been successful in getting it to load a game, either. I believe there are some utilities that I might be able to use, if I could get them to load. I've just been cautious with cartridges until I know the system won't cause any damage, given I don't know what is wrong. I live in the Maritimes on the east coast of Canada.

Ok, I tested and I have continuity between that end of the capacitor and both R47 and pin 4 of the 4013. Not sure what to try next.

One more addition: I think this chip has also been replaced. Is this the 4013 chip? The chip is labelled a TI 33A41D8 (The 8 may be a B, it's hard to tell). I can't find any info online about the chip, and I don't see any chip on the board with 4013 in the name. I see the 4013 in the schematics, but I find it hard to map schematic details to the pcb. Couldn't find a picture of a de-populated 7800 board online either. That means I can't easily figure out where R47 is located on the board, either.

So I've reattached the leg and tested around with my multimeter before turning it on. Everything seemed fine, but when I powered it on I got the same results. 2600 cartridges work fine, 7800 ones don't. Examining the board some more, I think this has been recapped at some point, and one chip looks to have been replaced/resoldered. I'm attaching picks of the parts of the board that looked worked on. Any further troubleshooting suggestions are welcome!

It's a good guess. Someone was definitely in this machine before me and that would explain the solder work. Unfortunately, I'm new to owning this machine, so I don't know for sure. It was working when my sister picked it up for me, so I'm hoping the fix is relatively simple. I also got a 5200 this weekend, complete with 4 controllers and a trackball, and was playing with that instead! I'll try to repair the 7800 later this week. Thanks for the details! I'll test it out with my multimeter before I turn it on again.

It's a little difficult to get a good picture, but here are a couple of angles

Just received a 7800 that seems to play 2600 games ok, but I only got a 7800 cartridge to work well enough to play a game once. When I examined the board, I noticed that the leg of the capacitor labeled c55 wasn't connected to the board. I'm planning on reconnecting it, but seeing as this is my first time using a 7800, I figured it's a good idea to check here first, to make sure it's not just a factory bodge. I'm going to do a second cleaning of the connectors first, but after a post-clean test, that's the next step as far as I can see.

Interesting. I wasn't aware there was the ability to save state to the AtariVox+. That would solve the problem, for sure. Guess I'm buying an AtariVox+!

Any UI would be an imperfect solution, given what you point out. Still, I'd be curious to see if there was a way to persist information and make it retrievable between cartridge images. My original thought was creating a series of carts that could lock/unlock areas or provide new functionality or abilities to the user based on actions they took on another cart (kind of similar to the use of a code to transfer your character to a sequel game back in the day, just automated). I haven't seen @rj1307 directly address this detail, so I was just wondering if it is possible.

The UI was actually just a chance thought following from my initial thought. The idea that made me ask the question was on the potential game/software side. Just wondering if there was some way to push data to the DragonFly cart so it could be shared between rom images and 7800 power cycling. I was thinking this could make for some unique mechanics, seeing as the Dragonfly stays on when the console is powered off.

@rj1307 I've been studying 7800 programming and I was wondering if you've exposed any hooks so that software running on the 7800 could send commands to the Dragonfly directly, such as getting it to load a game? Just wondering if it is possible, as that would allow someone to build an on-screen UI for the cart, or maybe a game using DragonFly-specific support. (Not sure what form that would take, just spit-balling ideas)

Please add me to the list: +1 (Pokey&YM)