MPC 2000 8 output problems...

So I have my MPC 2000 sync with Pro Tools 7 and Mbox 2. I have the 8 outputs on the back and am only able to track 2 at a time using the Mbox 2. (It only has 2 inputs.) Well I only have one cable for now, so I'm doing a track at a time into Pro Tools. I start with the output 1 on the MPC and have it connected to my Mbox 2. I record it and it works fine. I continue on to output 2 on my MPC. It records the second track fine in Pro Tools as well. So I go to plug my cable into output 3 on the MPC. Then I start the recording process. It doesn't play any sound and also doesn't record anything in Pro Tools. So I try output 4 on the MPC to see if maybe its just that output. It doesn't play any sound or record any sound into Pro Tools as well. So my question is, what's going on? Why does only track 1 and 2 record out of the outputs from the MPC into Pro Tools, but the rest won't? (I know its probably something simple or silly that I'm missing.) Well I appreciate the help, in advance.

I went to the mixer screen and assigned each track to an out. Such as track 1 to out 1/2 and track 2, to out 1/2 and so on. Is this correct? I don't have my manual with me so I can't verify.

can you even assign outs 3-8?
Is the output you chosen confirmed in the mixer screen?

I figured it out. It wasn't confimed I guess. I appreciate the help.

I forgot that the pads weren't matched to the track. So I had to match the pads to the outputs, not the tracks to the outputs. I basically did what you suggested. The correct way. Thanks for the help. (I didn't have my manual with me to check.)