I've got a 10 year old garage door that has started is starting to act up. About 60% of the time, when you close the door, it will go almost to the bottom (within 6 or 8 inches) and act like it has hit something. When it does this the door goes back up.
I can try it again right awasy and it might work or it might do the same thing. I've tried it 3 times and it worked then but other times you can try it over and over without success.
sometimes mine does that and it could be the sensor light hitting the sunlight and sences their is something in the way or readjusting the door for the open position. Hope this help out.
Give the door itself a general tuneup. Tighten all screws and bolts, lube all hinges and rollers. Adjust the chain if needed, making sure it's not dragging or binding.