First of all, the spring may need to be adjusted. Disconnect the door from the opener, it should be able to stop at any position in between open and close and you should be able to move it up and down with just your little finger. If the door want to close or open by itself, you need to adjust the spring tension. Second, the upper and lower stop position need to be adjusted, the door should reverse itself if a 2x4 is placed under. (your problem could be the lower stop position is set too far) Th
If sensor problem, it can not be 关上后马上自己就又开了 as described, it will not even begin to 关 at all. If the door can go travel the way down (关上后), it begin to reverse (马上自 己就又开了), it is the problem with stop limit position. It is designed to reverse if a 2x4 is placed under the door. Turn the screw a little bit each time, until you can find the door just shut right, but will reverse if something is stuck under (such as a piece of 2x4)
that makes sense. will try out this weekend. thanks!
each
【在 g*****9 的大作中提到】 : If sensor problem, it can not be 关上后马上自己就又开了 as described, it : will not even begin to 关 at all. : If the door can go travel the way down (关上后), it begin to reverse (马上自 : 己就又开了), it is the problem with stop limit position. It is designed to : reverse if a 2x4 is placed under the door. Turn the screw a little bit each : time, until you can find the door just shut right, but will reverse if : something is stuck under (such as a piece of 2x4)