Where can I get a schematic for a Chamberlain 5200 UBC garage door opener ?
I know the remote control is working as when I push the open/close button I can go on the main cct. board and see the signal on pin 14 of the LM2902. I can also trace the signal to pin 12 of the micro. The micro should do several things, check whether the door is open or closed, apply power to the relay motor, apply power to the relay motor to open or close the door. The controller works in the manual mode ok, i.e. I can open or close the door, turn on or off the light. It is very difficult to trace the circuit board as it has a ground plane on the top of the board and SM components on the bottom side of the board. I am unsure of two things, first the signal going to the micio is about 1 Vpk-pk and not the normal logic level or 0 and 5v, but if this input to the micro is set as an analog signal then level may not be an issue. Secondly I cannot determine what output pins on the micro control the power relays as it is almost impossible to trace the cct.
Anyway any help would be greatly appreciated ... thanks in advance and take care ...Vic