Oh you poor dear! I have had it happen with a design , however your situation sounds much more serious! Good Luck, sorry I have no suggestions. Live Laugh Download Stitch!

I guess you've looked on their website to see if there are any FAQs etc about re calibrating it?

You need to re-calibrte your hoops. If you join the PR600 yahoo group the process is in their files. I can see if I can copy the file and send it to you. I've had to do it to my PR600II but can't do it without the instructions.
Calibrating Hoop Sensor
As always, if you are under warranty use your dealer & warranty. If you have a good dealer use them. If like some, a dealer is a long ways off here’s a fix for you.
This info can be found in the Service Manual reference 4-33. First off make sure all thumb screws that secure the embroidery arm in place are tight. Make sure your hoop is on top of the hoop sensor, pictures 1d & 1e. If everything is as it should be you may have to recalibrate the machine to the hoop.
Turn off your machine. Install the Ex-Small hoop (40x60) and make sure the thumb screws are secured. Hold down the Start/Stop & needle threader buttons on the LCD screen then turn on the machine. On the screen you will see Hoop Type. Select the “S” icon. Now install the Ex-Large hoop (200x300). Secure the thumb screws. Select the “LL” icon. You’ve now recalibrated the large hoop to the machine.
Hope this helps.

HMMM! I'm afraid your machine may need to have the registration re-set.
This happened to my Designer Diamond after I had knocked the embroidery arm, actually the arm hit me. LOL!!!
But it was enough to stuff it up and it had to be professionally serviced to fix it....
hugs n roses, Meg

My Janome 350e hoop arm is at the back and needs 8" clearance. The first time it didn't it pushed itself out of alignment and cost £30 odd to have it fixed. The second time, after I'd had it a while, I crossed my fingers and pushed it back into place myself. It worked!. Jan