Japanese Mega Drive model 1 Region Checking?

[FoxNtd]

I just got a model 1 JP Mega Drive today; it's the first revision with the red lettering on the top near to the sides of where the power LED is. Anyway, I hooked it up via A/V and it works great with my Japanese Gunstar Heroes, so all seems well.

Then I tried an American Mystic Defender, expecting the game to boot up as Kujaku Ou 2 since, as they say, the game contains the data for both versions based on what model console you're on. However, flipping the power switch on does nothing. The game doesn't start, and the power LED does not light up. The power LED does work just fine as I had seen when turning on Japanese Gunstar Heroes. I tried both games 3 times in a row. All 3 trials with each game gave me the same exact behavior. And yes, I know my Mystic Defender cartridge is fine. It will play on my USA model 1 Genesis just fine.

I thought only a handful of Genesis games contained any kind of region lockout and Mystic Defender is not one of them to my knowledge.

I will have to test my other Genesis games to see if they work but I would like to know if this is a known issue. There are so many revisions of the Mega Drive so it can be tricky; I do not know if this issue has been witnessed before, which is why I would like to document it here and see if others have insight on this issue.

EDIT: After some digging around I discovered the meaning to "CARTRIDGE LOCK" that's written below the power switch on this model. Its purpose is to prevent removal of the game during usage. However I have a good feeling this is exactly why the system won't power on with a Genesis cartridge since the shell shape is different. I might have to look inside the console and perhaps rig it to bypass this feature. I'm sure I will never try to turn the console on without a game or try to remove a game without turning it off.

[Pikkon]

Just take the system apart and remove the cartridge lock,its just a piece of plastic,then most of your sega games will work just fine.