Having a problem with my Allister Access 3500 GDO not closing with the remote or a touch of the wall button, off & on. I have to hold the wall button down to get it to close. I replaced the safety sensors thinking this was it &, again, it has been happening. The new sensors don't have anything to hold them in place (i.e., wing nuts, etc), they just snap into the bracket so they don't always stay aligned. Any suggestions on how to get them to stay aligned? Also, if the wall switch, and/or the wiring to it is bad, would that cause the safety sensors to only work off & on or would that indicate a bad logic board?