Hmm... the seller says he cleaned everything before shipping, and cleaned the slot with an NES cleaning pad. Told me to rub the hucards for a good ten seconds with alcohol, also not to try taking apart the system because of the grounding plates and the fact that I might accidentally disconnect the board with the region mod.
So really nothing helpful. Dont really feel like trying to find an NES cleaning kit either. Guess back to searching for a better way to clean the slot because I definitely dont want to fool with soldering (still holding out hope that it isnt the mod that is the problem). Sorta good news...now i've seen a yellowish-green screen
I know this system has to work since at least the image with the CD saying PC with the 3.0 card is the same TG16 system (right down to small details like a small circle indentation where the TG16 logo is:
Unless it just happened to be an old image (but I dont think anyone would go through that much effort).
Read on neo-geo.com forums that you could perhaps use a cardboard nail file, slice the round end into a square, and use that, but i'm not sure how well that would work. Wouldnt that mess up the connectors in the slot by being too rough? Unless they just left out the part about covering the square end in some sort of light cloth.
The CD rom works perfectly as far as playing audio cds, so thats another good thing.
EDIT: On closer inspection, I noticed one of the gamebit screws on the bottom back right of the TG16 is missing, and the back end of the system is slightly more raised than the rest...I wonder if thats causing the cards not to connect?