This was after I tried
- Cleaning cartridge reader with rubbing alcohol
- Cleaning cartridge with rubbing alcohol
- Re-seating the 72 pin connector
- Replacing the 72 pin connector
I'm sad to say this console has never worked, this is just the last straw. I got it as-is at a garage sale >10 years ago. There are multiple problems. First was with what appears to be the PPU; the evidence is that a sprite layer is invisible. See how the placed pieces show up, but the piece-in-flight does not. And then there were problems with the 72-pin connector. Before re-seating, it was black screen. After re-seating, it showed the corrupted image.
It's tragic, the feature that makes me want the NES instead of an emulator (that tactile-ness of cart pushing in-and-down) is also one of the features that kills it.
I kept this console for parts, got a new one and it's working well.