Kotaku
An eBay user has four mustard-yellow NES repair carts, one grey one, plus a Legend of Zelda NTF2 cart up on eBay for the next five days. Starting bid is $850, no bids yet.
Siliconera has this to say about the rare carts:
Back in the NES era, Nintendo had official World Class service centers. These repair shops had a couple of yellow cartridges that ran diagnostic programs on a damaged NES. Unfortunately, if a NES suffered from blinking light syndrome the carts were rendered useless, since the cure for fixing the irritating flashing red light is replacing the 72 pin connector. Even though the cartridges are largely useless (except for the joystick test at the end) many collectors want them because they were not released to the general public.
Apparently these are from actual Nintendo service centers, some of them are in good shape and others have label damage. All apparently function, but $850?!
More here [Siliconera]
