I've got a bog-standard (B&Q, IIRC) up-and-over garage door, which has just gone ping.
I opened it the other day, to find the big coiled spring had come off the fitting at the end, so there's no tension whatsoever left - gravity is in charge. I had an attempt at refitting it to the end, but of course it needs to be wound on under tension...
Spring above the door -
The steel wires which hold up the door have unwound and just dangle uselessly
LH