Success! Replacement 72-pin connector didn’t work (shouldn’t have bought a random one off Amazon…), but boiling the OEM connector and vigorously clean the contacts on the board did the trick. Will write about my experience in the next Astrolabe!
My OEM NES has been 99% reliable with clean games since I boiled and scrubbed the connector over 6 years ago! Occasionally I run the 1Up Card cartridge cleaner through it. Glad you stuck with the original hardware; I hear those replacements often fail pretty quickly.
Let’s gooooo
repairing a broken NES with a hack-y home cleaning method brings me back to when i was a kid and did something similar with a friend. great memories.
IIRC one of the more common issues with the cartridge connector is the contact fingers eventually bending away from the cart PCB plane; I used a bent needle to pull mine back down a bit, plays like a champ. If mine screws up again it's boiling time though :V
nice work !