Cannot hear midi sounds through Mbox 2 PRO

[renehubard]

Hi, below a list of the hardware/software I am using:

*Computer- MacBook PRO Retina Display (15")
*Software- Pro Tools 10
*Audio Interface- Mbox2 Pro
*MIDI Interface- MOTU Fast Lane
*Midi Controller- Yamaha P-85 Digital Piano
*Midi Sound Bank- Roland RS-5 Keyboard

I have the following connections:
*Mbox2 Pro connected via Firewire to computer
*2 Powered speakers connected to Mbox2
*MOTU Fast Lane connected to computer (USB)
*Yamaha P-89 Midi Out to MOTU Fast lane Midi In
*MOTU Fast Midi Out to Roland RS-5 Midi In
* Two 1/4 inche Lines from Roland RS-5 outputs (L&R) to Mbox2 PRO Aux (Channels 3 & 4)

The issue that I'm having is that I do not hear the midi sounds generated by the RS-5 through the Mbox2 Pro. I see Midi signal coming into Pro Tools when I play my controller keyboards, and I can record MIDI just fine, but I don't hear anything while recording. The same thing happens when I try to playback what I just recorded: I see midi signal coming out of the MIDI Interface and I see signal coming into channels 3 & 4 of my Mbox, but no sound through the speakers or headphones (the only sound I hear is a super short echo of what was being played back when I press Stop on Pro Tools).

The weird thing is if I switch the 1/4 inch cables out of the Mbox and into an amp I CAN hear the sounds from the Roland. Another weird thing is that if I connect any other instrument to channels 3 & 4 of the Mbox I hear that instrument fine too (I even hear the sound of the disconnected cable).

So I am not sure if it's a MIDI issue or a problem with my Mbox 2 or a combination of both. Any help will be super appreciated!

BTW, not sure if this has anything to do with my issue (it might not be related at all) but might as well share just in case: When I ran Audio Midi Setup it only located the Mbox 2 Pro and FastLane USB. I had to add the keyboards manually by adding a device, entering the device name and manufacturer. I could not find the model for my Yamaha keyboard on the dropdown so I entered it manually. I didn't change anything on the "Transmits", "Receives" & "Features" sections of the devices.

Thanks.

[renehubard]

I figured it out. I created an Aux Channel in PT and assigned Ch 3 & 4 Ins.