Would all of the Phoenix Wright original DS games work on my 3DS?

This winter they will be releasing HD versions of the original trilogy on the 3DS eShop. So you can get those there.

As for the other games in the series I don't know for sure. The 3DS can definitely play DS games but if yours has trouble with that there is no way I can tell you if it'll work or not. You'll just have to try it for yourself or wait and see if they ever release those other games on the 3DS.

What sort of trouble does your 3DS have with DS games? Every Ace Attorney game worked just fine on my 3DS, but so has every other DS game I've played.

If you're concerned, the first three games will be released digitally for the eShop later this year. The newest game in the series is a 3DS game. That leaves two games in the series playable only on the DS.

Normally a 3DS can play all DS games. If your's is giving you problems with DS games, however.....

How should we know, we don't know what's wrong with your machine.