hi guys i have had this ongoing problem.....been on to Roland & they assure me my Quad Capture is all set up fine....i can see playback on screen but no sound out my monitors....had these sorts of problems for the last month....im only new to Sonar Platinum & have only recently started with computer recording...so please talk in laymans terms.....if problem persist i can see me throwing the bloody lot out of the window!!!!!!!!!!!!!!!!!!!

First, sorry for your frustration. I've been there.
 
Now, to run this down without coming over to your house, I'll need some help from you...
You say you can 'see playback on screen'. Does this mean that levels bounce in the 'MAINS' Bus? Where is the MAINS Bus routed?
 
Does the Quad Capture have an application that you can open where you can see signal moving for the inputs and outputs on the quad capture? Do the headphones work on the quad capture?

i have levels in the mains bus...mains bus is routed to my quadcapture.....have no volume in headphones either.....would be nice if you could pop over lol

Most of the times when someone say's they can't hear playback it's because the master buss is not routed to the interface properly. Example it's set to the SPDIF or the 3/4 when your monitors are connected to the 1/2 outputs.  
And as said above if the interface comes with a GUI mixer check that first. 

The tech man from Roland has just remotely set up the Quad Capture....about 2 hrs ago

When you open the quad capture program, can you see the levels bouncing or no?

just opened another track & it seems i have sound could there be a problem with particular Tracks?????

Do you have mute enabled?
 
Here's a picture showing routing...
 

 
From the Console view you can drag in the buses and the outputs so you see what is routed where.
 
You want to make sure you aren't SOLOing or Muting the tracks you are trying to hear. There are Solo and mute buttons on each track.

You post is becoming confusing to me. You said this:
"i have levels in the mains bus...mains bus is routed to my quadcapture.."  
 
And now your talking about "tracks" ? 
I would say you haven't set your track outputs correctly, but from what you say above  then this would not be the case. Normally tracks will default to going directly to the 1/2  output which results in sound.  If the meters are moving in your mains output bus 1/2 like you have said and your monitors are correctly attached to outputs 1/2 then there is sound. The meters will not move if you muted the buss.  If meters are moving there is a signal. But this has to be the correct output as I said. I'm not sure how many outputs you have but double check your correlating the meters with the same outputs the speakers are using. 
We can only hope that you have correctly set your interface and monitors up correctly now as you have said the tech walked you through this. And that if there is a software mixer he helped you set that correctly too. 
 
If you insert a "Master"  buss as shown in gswitz screen shot, then you send all your track outputs to that first. Then the Master buss is output to Main 1/2. 
 
 

Cactus Music
You post is becoming confusing to me. You said this:
"i have levels in the mains bus...mains bus is routed to my quadcapture.."  
 
And now your talking about "tracks" ? 
I would say you haven't set your track outputs correctly, but from what you say above  then this would not be the case. Normally tracks will default to going directly to the 1/2  output which results in sound.  If the meters are moving in your mains output bus 1/2 like you have said and your monitors are correctly attached to outputs 1/2 then there is sound. The meters will not move if you muted the buss.  If meters are moving there is a signal. But this has to be the correct output as I said. I'm not sure how many outputs you have but double check your correlating the meters with the same outputs the speakers are using. 
We can only hope that you have correctly set your interface and monitors up correctly now as you have said the tech walked you through this. And that if there is a software mixer he helped you set that correctly too. 
 
If you insert a "Master"  buss as shown in gswitz screen shot, then you send all your track outputs to that first. Then the Master buss is output to Main 1/2. 
 
 

This ^^^