I have a Sears 3/4 hp GDO that is approximately 5 years old. It hasn't ben working for the last year or so. It was doing some extra work due to a door alignment problem. I also had a wiring issue that I figured out by taping the safety sensors together (yes, for diagnositc purpose only!). Before I went through the trouble of replacing the wiring and remounting/adjusting the chain I decided to push to open button on the wall switch. The motor starts and runs for 3-4 seconds in the counter clockwise direction and then reverses direction for the same 3-4 seconds. I expected it to run for the usual 7-10 seconds and then stop. This doesn't seem normal, does it? Do I perhaps have another problem? I did check the internal gears and they all seem fine with plenty of grease etc. This site has excellent posts regarding GDOs and I have already learned a lot. Thanks in advance for any advice you can give!