Non-working Megadrive cartridge

[moonwhistle]

I recently got a Rainbow Islands Megadrive cartridge and it simply won't work. I've tried all the usual trickery, cleaning the hell out of the contacts with alcohol and inserting it into the slot different ways but there's no sign of life from it.

I been through hundreds of carts in my time and this is the first one that refuses to work. Any idea what the problem could be, or is it simply a faulty rom chip / lost cause?

Thanks.