On Jun 24, 10:27*am, dpb wrote:
On 6/24/2012 9:23 AM, Vic Smith wrote:
...

If it's balanced as you say, and moves freely with the opener
detached, there's only a couple things left.
1. *The motor is failing.
2. *The chain or worm is binding.
Check if the spring guy moved the opener chain/worm rail off-center.
You might also test the pulling force of the motor manually, but be
careful.
Otherwise it might be time to replace the opener.

3. The two springs aren't equally adjusted even though overall tension
counterbalances weight...

4. Hinges are binding

5. Track alignment is amiss or rollers/etc. are worn to point of causing
misalignment/binding...

6. Variations of any/all of the above...

--

I'd add to the above list:

The force limit may need to be adjusted on the opener. The ones I've
seen had one for the down force and one for the up force. It's a
safety mechanism to stop the door if it encounters too much
resistance.
If it's set too low, just normal opening could stop it.