20 Most Recent Chamberlain Powerdrive PD422D 1/2 HP Security Plus Screw Drive Garage Door Opener - Page 2 Questions & Answers

Try adjusting the force of the opener. Instructions are on page 25 of the manual. http://www.liftmaster.com/CatalogResourcesV3/en-us/shared/files/tucmanuals/114A3059.pdf

take some toilet paper, or some very light rag and dust the RPM sensor over, under, inbetween and in every spot on that darn thing, and bingo, it will work. Its the plastic ribed piece mounted on the end of the motor under opener cover. If something gets under door as door starts to go down, the RPM`s will slow and thats a warning to stop and go back up. With it being dusty, it can`t sense the RPM`s properly and goes into an alarm every single time. Ugg

Phone the garge door doctor (Allready)

My battery is bad. I knew it, but did not feel like it was worth any of my attention. The beeping started yesterday and this was worth my attention. Everyone in the family complained. I suspected it was the battery.

I unplugged the unit. Disconnected the battery. Waited for 30 seconds. Plugged it back in. It works fine and no beeping.

I suspect it is a warning to replace the battery.

most likely there is a safety overload switch that will stop if the rollers on the track ( the steel that the door rolls in) is dry and needs to be greased so it can roll in the tracks freely also check the chain for the same, the chain drive should be free of any junk stuck on it ,the chain should not be to tight or twisted in any way, if it seems to be leaning one way or the other twist it straight with a pair of pliers also be sure its power source is not share with any other appliance. let me know of your progress.

see if there is a rubber hose trim along the bottom edge and that it has no holes or cuts also a small rock or pebble could trigger it to go back up