Game Boy Action Replay fault

[AndehX]

I have an Action Replay for Game Boy that has worked fine in the past, but has sat on my shelf for years now. I plugged it in last night, and got nothing from it. So I pulled it apart and started probing with my multimeter. I found nothing unusual.
So I tried simply reflowing the pins on the cartridge slot, and on the chips. Low and behold it sprang to life. Yay. I assumed it was fixed, and went to bed.
Tried it again this morning, and it's broke again....

So I got the WD40 out and really went to town cleaning all the pins and even used a bit baking soda to scrub the oxidation off the pins. No dice. Still not working. Tested continuity on all the cartridge pins, they all check out fine.
So I am stumped, I have no idea what to try now. I am 99% certain it isn't as issue with dirty pins or anything that simple. I've also tried replacing the resistors with newer ones. No difference.

Anyone have any ideas what I could try next? Here's an image of the board:



And a video to show what it does:

https://www.dropbox.com/s/jp4gq5py4y4cv ... 9.mp4?dl=0

[nmalinoski]

I have an Action Replay for Game Boy that has worked fine in the past, but has sat on my shelf for years now. I plugged it in last night, and got nothing from it. So I pulled it apart and started probing with my multimeter. I found nothing unusual.

Could it be the GameBoy, then? When was the last time you cleaned the cartridge slot? Are you able to try the Action Replay in a different, known-good Game Boy?

[AndehX]

I've tried it in an original Game Boy and a Game Boy Advance, it doesn't work in either of them. I have had it working in both of them in the past too.