Previously Stereo tracks now only play in one channel

Hi,
 
Its been a while since i've sought some help here but this one's got me perplexed!
I have only recently put my studio back together after moving house. (Oh what fun)
I am running a couple of older Motu units (24i and 2408 mk 11) and using Sonar Prod 8.5
I was playing back some previous projects and only seem to get 1 channel. ene tried straight out of the Motu unit and only 1 channel there.
Assume its a setting in sonar as both Motu's doing it. Even reinstalled the motu drivers but no change.
Would appreciate some helpas i'm slowly going mad.
 
Thanks
Harry

Thanks Bristol_Jonesy.
I'm connected directly from PCI card to the motu unit and i've tried my headphones (2 sets) directly from the front panel of each of the motu units and theyre both same, 1 channel.
I usuall run the two main outs from the motu to my desk and then from the desk to the studio monitors.
i feel that its sonar related. i did have my anti virus changed and updated since i used it in the studio last and that may have upset it but i dont know where to go in Sonar to check.

Im Stumped !!
Have uninstalled Motu drivers etc and re installed in accordance with Motu's instructions.
Sonar however is a different matter and i cant for the life of me work out why its doing this.
i can play all sound files perfectly through Windows media player etc through my small pc speakers, but when i launch Sonar and play a project back (defaults to the Motu soundcard) i only get one channel.
Tried different cables, two different Motu units (24i & 2408 mk 2)
could it be a conflict between Sonar and the virus protection?
if so is it likely to only manifest itself via the Motu soundcard and not in windows?
Help,

You confusing yourself by using the on board sound card if that' s what your saying when you used the PC speakers for Media Player.
Did you do what Bristol advised and swap cables?
This is the first thing an engineer/ sound tech will do if a side goes down. You start with the speaker leads and work backward through the cables.
Swapping speaker leads= Not the speakers or cables.
Swapping inputs to power amp= Not the power amp
swapping at the output of mixer/interface =not the Cables and now will tell you if there's a dead channel. ( you could start here too!)
So if swapping the output leads of the interface results in you finding say the right channel is dead:
Check the front controls are all set the same.
Check your interface software mixer is set properly
Control panel sound and audio devices check if that interface is the default.
Do as Bristol says and see if left and right meters are showing in any playback program.


 

Wrong card post removed
 

 

Johnny - no, the MOTU 24i and 2408 are both PCI (for MK2) based cards with breakout boxes attached to the PCI card.  the breakout boxes are 1U with several I/O channels on each of them.  and the pic you have shown is for an EMU USB soundcard, not MOTU.
 
I figured it must have been something like that!

Thanks Bristo and Cactus.
Yes i understood what you meant and i appreciate your help and advice.
I have found the culprit, it was a setting in the SMPTE console within the Motu software.
Strange because that has never been an issue in the past nor have i needed to go there!
But that's what makes this field so challenging.
That was the reason it didnt make sense to me. i knew all my cables were fine as i had already eliminated those errors from the signal chain but knew it was originating from either Motu or Sonar.
Thanks to everyone for their help, if it wasn't for these forums i for one would definitley have no hair left, you've saved me before in the past as well.
Thanks again to all, now off to create..!
 
Harry

yeah, good thing he figured it out becase I'm sure none of us would have ever guessed to have him checkthat.