I think someone ruined this Battletoads cart

[Ziggy]

I'm not sure if this is at all applicable to the humble Genesis, but thought I should explain why I suggested it.

It is, actually, you're right. There's up to three address lines that might not be used depending on the ROM size. There might be other pins as well, but there's three address lines that I know of. So if, for example, the A21 pin is very dirty, a smaller sized game might work fine while a larger size game doesn't.

But that's not the case here. I just checked and Castle of Illusion is only 4Mbits.

[KDub]

Yeah it is the cart. I took apart the Genesis and recleaned the contacts and then played Kid Chameleon for a long while and nothing.
Popped in Castle of Illusion and when I got to right before the boss in the second world, reboot.

Tried to get some close up shots of the Battletoads cart but the Macro mode still won't focus on them for some reason.

I've cleaned both what feels like a hundred times each now. Never had problems that have been this frustrating since I bought a Quattro Adventure cart a year ago.

[KDub]

Little update

So I had a quick idea to test what the Battletoads cart was doing. I had tried before to use my Game Genie to see if it just wasn't making a good connection, hey it isn't a NES but it was worth a shot. After getting past the Game Genie screen I had the same issue, black screen.

Well I was looking at my games and I saw my Sonic and Knuckles cart and thought "Hey, why not?". Usually when you pop in an incompatible cart with Sonic and Knuckles you get that "No Way!" screen, with my Battletoads cart it just skips straight to the the main title screen. I would think that even with corrupted data/signal the Sonic cart would still see that something is plugged in that shouldn't be there. But it just acts like nothing is there at all.

Seems interesting, but I could be wrong.

[Ziggy]

Hmm, good point. Even if the ROM is being read as garbage, I would assume you'd get "No way!" on the S&K cart. That does sound like it's not reading it at all, like it's not even there.

Did you ever check over all the traces? If the right trace is damaged, that could do it.

Getting ahead of that a little... If all the traces turn out to be good, I would probe the cart when it's in the console and powered on (be careful, of course) to see what the voltage is at various points. If your multi meter can test capacitors, then I guess you can test the one on the cart (even if it looks alright) but I would think that you can assume it's OK if you test the voltage before and after the cap. Anyways, if all the traces turn out to be OK, and the voltage looks good, it might be safe to assume that the mask ROM is dead. For whatever reason. I can think of two ways to test that. One, swap the mask ROM with another game (of the same size) and see if both the carts still work. Or two, read the mask ROM in an EPROM programmer, but I'm assuming you don't have one.

Either way, first thing I would do is check over all those traces. Did you do that yet?

[KDub]

Nothing looks in bad enough condition to not send a proper signal. In fact besides some rubbing and minor surface scratches on the green nothing looks touched underneath the coating.

But I can't find my multi-meter so I'll need to go buy one to do a full test. Which is why I was trying to other things to double check before I went out and spent more money on this.

[Ziggy]

I had a multi meter curse for a number of years. Either they went straight up missing, or my Crasftman that broke a whole 5 minutes after I got it.

[Hateshinai]

I don't think that it will help the original poster but I want to share my experience.
I got a "Tempo" cart for the 32X and it wasn't working at all. On opening it I found that one of the contacts had a rather large piece missing from the middle (all the way into the underlying board) and so the circuit was broken.
It did not seem to me that solder could bridge the rather large gap and still be thin enough to insert into the console. Then I remembered my basic sciences from school: namely that graphite conducts electricity. So I took a good old fashioned pencil from my sons schoolbag and literally just drew the missing part on the board...
Worked like a charm. I suppose that eventually I will have to redraw the missing piece since it will rub off with use but for now (about 6 months since my "repair") everything is fine.

[KDub]

^ That is awesome. Talk about some DIY rigging haha.

[Ziggy]

Worked like a charm. I suppose that eventually I will have to redraw the missing piece since it will rub off with use but for now (about 6 months since my "repair") everything is fine.

If you ever have to fix it again, I can think of a more permanent solution.

I don't know how large the gap is, but is it something like a centimeter? You can get solder to bridge that, but you'll pretty much have to tin that pin with solder. Solder isn't the best thing to be using, long term, I think it's too soft.

You can use any kind of metal that conducts electricity well, just make sure it's thin but wont scrape apart (from inserting it into the console over and over again). You can get some glue that conducts electric, and basically just glue a thin strip of metal down over that pin. Maybe the glue can fill in the gap, and clamp it down nice and tight while the glue dries.