NES only works without cartridge bay

I am having a bizarre issue with an NES I just bought and I am unsure of how to fix it. I was getting the black screen of death. I opened it up and deep cleaned everything in it including the 72 pin. Before I place the cartridge tray back in and over the pin connector, the NES will read and play just fine. When I put the cartridge tray back in and seat the game that way however, it returns to the black screen of death. It looks like it has been worked on before and the cartridge tray itself seems raised a little bit too high over the 72 pin connector. Does anyone know the solution to this? Do I replace the 72 pin or the cartridge tray?