yep. It says bugger all on the board from what I can see but from what I've read, both the MD and Game Gear have the same polarity. Yakumo
Special Partners are ok as far as copiers go. My cousin's uncle in HK sent us a boxed one during the SNES days to play with (since carts were like 80 dollars each), and I still have it, as well as another unit I picked up. Actually I have lots of Chinese copiers, since I basicly got them from all my cousins and family once they lost intrest in theirs. But as to the copier, the thing with Special Partners is that it doesn't respect Game Doctor format disks properly. If you name the disks in a particular way, it won't fall out of GD specs, but for the Special Partner, it won't read the files. It won't detect the total number of disks and will stop asking after a point. As far as the game loading goes, the Special Partner just has several 4mbit banks (from memory). I think I have a GD someplace that has 96mbits of DRAM in it and it supports multiple games just fine. Just depends on how large each game is (Bare in mind GD's use 8mbit banks). The one benifit copiers like the Super UFO's and Special Partners have is that because they can partition files in 4mbits sometimes you can save an extra disk's worth of loading because of it.
It looks dusty as hell but not leaking from what I can tell. Maybe it would be worth changing it? Yakumo
It's definitely leaking and appears to have corroded a little bit of the PCB. This is very normal though with all copiers and is very unlikely to affect it's operation. It will probably need to be replaced in order to hold a save. I'm not sure of the exact cause of all the leakage, but it's either to do with A) no or broken cell protection circuit or B) cell fully discharging.