certain FC games not working on NES (toaster)

[gyuuu]

Hey there! First time posting here, I have a question and this seems like the right place to get an answer.

A year or so ago I snipped 10NES chip and bought a 60 to 72 pin converter, and I've been playing famicom games on my NES-001 front loader with no problems. A couple of games however have some issues and I'm wondering if anyone else has run into anything like this.

Double Dragon 2: the screen just flashes different solid colors and the game never boots.

Dragon Buster 2: the game starts just fine, but the map screen after the title screen is scrambled. Every now and then I'll be able to enter a dungeon, which plays just fine but it won't load any of the items (like the key) needed to complete a level. What's odd about this one is that it worked just fine the first time I played it, but every time since then it's done this.

I tried out both of these games on two different NES consoles, and it happens on both of them. I also bought a second copy of each of the above games thinking it was the carts, but even the second copies have the exact same issue.

As far as I know, neither of these games use any special chips or use the famicom expansion port in any way. Is it possible this is due to my adapter? That's the only point of failure I can think of that might cause this problem, and it's the only piece I don't have two of so I can't test it on another one. Is there any reason why certain standard FC games wouldn't play on NES hardware?

Thanks in advance! Looking forward to posting here more.

[xIceMan]

This is most likely a region issue. Are those PAL or NTSC games on a PAL or NTSC console?

Playing NTSC on PAL console or vice versa may lead to such results.

[gyuuu]

It's a US NTSC NES and the games are NTSC-J famicom carts. As I said before, other famicom games work just fine, and I have quite a few of them.