Repro cart stop working over time?

I made a nes game and it worked great. Then I put in a box and didnt move or anything for few months. Tested today and it wont work. Get black screen. All other games work.
Ill check for continuity on the wiring. Wires look fine. Guess what wondering is can the solder get loose or anything that would cause a repro to stop working when it hasnt been in use over time.

Using 5V parts, not 3V parts, right?

Used M27C2001 EPROMs. 5v right? Could it be the wires? Using Ethernet cable wires.

I'm going to resolder the wires. The 5v at least on both chips.

It's a TKROM for Mario Adventure.

Yeah, mechanical flexing causing failure of whatever seems the most likely

mechanical flexing? The board?
Was wondering if it was my 72 pin connector but other games work. Did notice there is a give a little when I pull games out but this repro feels loose.

I've fixed the 72 pin connector. Sigh... I need a top loader so I can test and know for certain.