Garage door hinges keep sectional doors together and are also the connecting parts between the door and the rollers. They are extremely vital and when broken, the door must not be operated or it will be a safety hazard. Hinges do not break easily, unless they are very rusty or made of very thin steel materials. They will also break if put under a lot of pressure with a door much heavier than the weight they can withstand or if they are hit with a heavy object, like a car. They usually need maintenance with lubricants and tightening of their bolts.
Broken garage door hinges will not hold the different door panels together. If the hinges connected to the rollers are broken, the door won't move properly and will be unsafe. They must be replaced at once and only with the door open, c-clamped and the opener disconnected. To avoid similar problems in the future, choose hard steel and also make sure the replacement is done by a professional to ensure proper installation.