20 Most Recent liftmaster Chamberlain Garage Door Opener Transmitter 300MC - Page 4 Questions & Answers

Click the learn button on the receiver followed by the remote. See e.g. http://www.liftmaster.com/CatalogResourcesV3/en-us/shared/files/tucmanuals/114A4109.pdf

Not much to a single button remote. You need to match DIP-switch patterns between transmitter and receiver. See e.g. https://www.youtube.com/watch?v=PmbgqS6Ijs8 found here http://www.aaaremotes.com/lichgadooptr.html#.U_wZnvldV8E See also Liftmaster learning mode how-to: http://www.liftmaster.com/CatalogResourcesV3/Rightnow/Misc/Program_Remote/proRemMenu.html

The receiving unit usually has an led that lights when the sending units light is aligned correctly to let you know its ok.

Maybe time to change the remote battery? Many remotes also suffer from poor solder joints where the battery terminals are. Check the terminals and re-solder as needed.

From what you say something is interfering with your remote. This is a hard one to fix and there is no one solution. If you know an amateur radio operator ask his help. First I would turn off all computing devices (UPS's included) to see if that resolves the problem. If not Turn off all breakers except the one with the lift master. If that resolves the problem turn on items one by one. When you find the circuit you need to disconnect each item one by one until the problem goes away. If not check for other items on the same circuit and battery operated devices such as other remotes, phones ..etc. If that does not resolve the problem then it is probably one of your neighbors. See if others have openers operating in the same frequency area and are they having troubles. Try: http://transition.fcc.gov/Bureaus/OPP/working_papers/oppwp38chart.pdf to see what operates on what frequency. There is also the possibility of harmonics from 100 MHz. You may also want to contact LiftMaster.

There is a pairing button on the opener back top. Follow the directions on the new remote

disconnect the power and try to pry the prong in the socket of the light outwords,check the connection in the unit itself

It could be. As I recall, the gears are nylon composite gears so they could be stripped out. First, check the force adjustments to be sure they are adjusted correctly. If the UP force is not adjusted properly, the mechanism could be slipping and the door not opening. Try adjusting it to see if the door will open and close properly. The DOWN force adjustment is for making sure the door seats properly and should not impact the door closing unless you have it set too high, in which case it could be trying to exert excessive force on the door when closed. If these simple fixes do not work, look at the owners and parts manual you received with the opener, or check on line to see the exploded parts manual page from Chamberlain and see if the gears are available before you attempt to dismantle your opener. If you don't have experience in mechanical repairs, or the opener is old, it may behoove you to purchase a new opener on sale with a new warranty. Usually, gears that strip are from a door that is too heavy for the opener, an opener that is of insufficient power for the door, a door that is not properly adjusted and places too much strain on the opener, or an improperly adjusted opener.

error code 14: is telling you that your sensors (6" off the floor) both sides of garage door are misaligned. check sensors, make sure the lights are on, move them around and tighten them down

If the sensor sees something under the door, it will stop and blink the lights. So I think you need to check out the motor, there's dial to increase the lifting strength.

Check the photo eye, if it is mis alligned or broken it would cause this type of problem.

No. The sensor is infrared so sunlight shouldn't affect it at all. The sensors are set up so they send a signal to each other, thus the need that they be carefully aligned. They work fine here in the California bright sun where it streams through my open door most of the day.

it needs adjustment, there are usually an adjustment knobs on the unit it self, (check from the owners manual)...

yes very much they both need to be green just try to line them up , good luck

Most garage door operators (openers) have infrared safety "beams". The door won't close, even with a wired push button, if something is in the way.

check the safety photocells is theres not obstacle between then, check both photecells leds are on.. otherwise no need to replace them