Controls not working correctly in Super Smash Bros Brawl

My brother bought Super Smash Bros Brawl a couple of weeks ago, and ever since then the controls have been acting up. The game will interpret a single button press as multiple ones, and it will continuously go in and out of sprint. This has made the game unplayable in the campaign, but when I play against him in versus, the controls are working just fine. I don't know what else to do to fix this, I've tried cleaning the disk, replacing the remote's rechargeable batteries with regular AAs, and updating the Wii. The last thing I can think of is formatting the Wii, which neither me nor my brother want to do. The Wii has been sitting in storage for several months before, and the problem only persists with this game specifically. Is this a glitch, and has anyone else experienced this? And how in the world do I fix it?

UPDATE: During the pause screen, something caught my eye. The game controls would continuously switch between nunchuck mode, and then a different one without the nunchuck. So what I did was I blew any dust out of the nunchuck connector, and the problem lightened up by a little. It was then that I noticed that the connector was loose, and would keep wiggling in and out of the remote. So now the question is how do I fix the nunchuck connector?

Solution 1:

I've had this almost exact same problem with my Wii. What I always did was to use my Classic Controller since it was only specifically with my Wii Remote alone. Only problem with this is that it became unresponsive to every push of a button and i just stood there. What I would suggest would be to either get a new Nunchuk, or to check if any buttons get jammed momentarily. Best of luck!

Solution 2:

It would seem to be that the nunchuck is causing the issue, since cleaning it off helped some, but then its odd that it only happens in that game mode...you could try playing story mode without the nunchuck just to check if it works, if it does then either use a new nunchuck or play without one. Tbh you are best off just getting a gamecube remote anyways

Solution 3:

Try using the game without the nunchuck. Otherwise, clean the part of the wii remote that the nunchuck goes into and clean the part of the nunchuck that goes into the wii remote.