Discuss PGroot's answer to: How to determine broken garage door springs?

If a spring is broken, the wire inside keeps it from falling apart, but you can find the break.  The door may open crooked, or not open all the way.  And when it's open the broken spring won't be stretched out. 

If you replace it yourself, bring the broken spring to the hardware store.  It's easy to get the wrong spring that looks almost right, but it won't open the garage door properly.  The part number is important.