STi not capturing images

Help! A couple of days ago my STi was working fine. When it connected I would hear the shutter clicking and it would capture images without any problems. Tonight I set up and starting trying to calibrate guiding, and while PHD connected to the STi, I heard no shutter sound and got nothing but dark frames from the camera. I tried with CCDops and got the same - camera connected but no shutter sound and no image, just dark. Tried: unplugging all other devices, and new usb cable - no difference. Pulled the camera out of the oag and the shutter flops open and closed with gravity, but doesn't open when I grab a frame. Turned the camera so it would open and shined a light onto the sensor, but still no image. Seems broken, though the kit has been treated with nothing but TLC; haven't removed it from the oag since I got it focused, and haven't removed the imaging rig from my ota for a couple of months. Anything else to try?

I purchased the STF-8300m package that included the camera a little over 2 months ago from OPT, so it is still under warranty, but I can't image without a guider! Thanks for any assistance you can provide!