I've replaced the connector on 6 Nintendos, they all originally worked better, but still have problems. The four I had wouldn't even work before I replaced them. Of the replacements, two quit working entirely, two work sometimes, and two work fine. Four of these were completely refurbished. I took two back and they got the second set of pin connectors, and they worked good for awhile. On the other hand, I've had three Nintendos, with the original pins that worked fine. It's hit and miss. I didn't play a lot of Nintendo back in the day (I went from Atari To Genesis) so I didn't realize the enormous rate of malfunctions the Nintendo had. My brother's original Nintendo from 1990 quit working last January, and has had two sets of new connectors. It still doesn't function properly. My ex-wifes Nintendo from 1988, quit working about the same time, and it too has issues, but works better than his.
For example, today I was playing a non-alterted Nintendo, some games worked, some didn't, but when I was playing Ninja-GAiden, after about fifteen minutes, the screen rebooted, and started blinking. I have never seen that before.
I also have a retron, and sometimes games won't run on that, so I don't always know if its the game, the system or both.
On the other hand, I haven't had any problems with my other systems.