My power went out last night and now my garage door only opens about 85% of the way and automatically goes up when it touches the ground, any idea how to reset it.

SOURCE: garage door opener troubleshooting

Try backing off door travel ajustment,

SOURCE: Chamberlain Liftmaster Professional 1/2 HP

Okay...upon further inspection, my left spring has broken in two. Going to call around for some quotes to replace the spring. Thanks for the suggestions.

SOURCE: GARAGE DOOR OPENS BUT WILL NOT CLOSE AUTOMATICALLY

is bulb on motor flashing 10 times. then you have electric eye problem. otherwise, sounds like you need to increase down force a hair. adjustement is on logic board, right knob.

SOURCE: my garage door goes down

check again. blinking 10 times. electric eyes are blocked/dirty/misaligned.

SOURCE: After opening, my automatic garage door creeps back down a bit

There is a sensitivity switch for both directions, open and close. If you access the garage door opener in the ceiling, you will see two adjustment screws for calibrating these. I would highly recommend following the instructions in your manual, as these are life safety adjustments! Your sensitivity for closing the door is adjusted to the positive. You just need to back it off a little. Place a 2x4 on the floor of the garage where the door comes down. and when the door hits the 2x4, it should automatically come back up. If not, you adjusted it too far. Hope this helps. and remember, check the manual for your specific adjustment procedures.