How can I fix the door of my Panasonic NN-T543W Microwave?

I have had a problem with this beastie for a while now. When I pressed the door open button, the door would be released but not fully open until I pulled it. Now the door is closed but pressing the open button does nothing? There is no resistance left to the button and I don't want to force the door open to try the "Rubber Band" remedies suggested by others without first asking if prising the door would do more damage?
Please help???