Need help installing a hardware synth

So i bought a nord rack the other day and am having problems setting it up in cubase 5. Im using a novation mkII as my midi controller as well. I have it set up right now with midi out from the rack to midi in on the mkII and midi out on the mkII to the midi in of the rack. For the audio i have a and b outputs on the rack going to my interface (m-audio fast track pro).
In cubase Ive set up the nord as an external instrument step by step from the manual and when i turn knobs it seems to be recognizing it as theres no sound. In the vst connections my inputs and outputs are the interface which I believe is correct.
Any help would be greatly appreciated as Ive read many other posts and the manuals on how to set up and it seems like Im doing it right. Thanks in advance

FWIW - i found that the “external instrument” feature in cubase to be a bit cumbersome. I find it simpler to set up the external instrument(s) with the midi inputs and outputs from your midi interface (if you are on a mac you do that in the audio/midi setup - not sure on a pc) and audio outs from the instrument to your audio interface and then label the vst connections accordingly.

then when you write a midi part to send to the external synth you just select it as the midi output destination on the midi track ( make sure the track is monitor enabled if you want to play live) and select the midi keyboard as the input to the track. lastly create an audio track and select the instruments outputs as the source of audio and voila.

HTH

Turns out it was an interface problem and not cubase whic makes me feel better. Works perfect now tho and it was super easy to sort out