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

canucksgirl5 years ago
I did a google search and I see this question has been asked at several sites, so if this was you Vic, I imagine you've had this problem for some time now.

My first concern is that Chamberlain does not show a 5200 UBC model on their website. It seems that people do have difficulty determining their actual model number. If this is the case with your situation, you can find your model number through the help at this link:


Beyond that Chamberlain does have manuals that you can download here:


Again, the 5200 UBC you mention is not listed.

There is also an FAQ page that offers technical support, you can find that here:


Lastly you can contact Chamberlain directly for help here:


I hope this helps you in solving your problem.
lazerspot (author)  canucksgirl5 years ago
Greetings ... thanks for the reply and yes I have no trouble with finding the model # on the unit as the aluminum sticker on the unit shows it loud and clear. What the problem is the unit was manufactured in 1999 and is probably not supported any more nor is there any unit on their website that even looks like it ... as they say time moves on and so do products. I did in fact contact the company and their reply was essentially go jump in the propriety lake and I also went to all of the websites you listed but I know the nature of the problem requires a schematic or a lot of my time tracing the circuit board.. Of course I will never buy anything from them again as I don't like that "go to hell" attitude of customer support. It's all this kind of corporate garbage attitude that is causing the kind of problems we are having with the economy. I have two identical unit and when the other developed a problem I was able to fix it as the problem turned out to be a bad relay driver transistor, a 5 cent item I may add. Imagine having to spend another $200 for another garage opener just for the sake of a 5 cent transistor ... poor design !!
Anyway its no big deal ... I will either solve the problem or use the manual buttons to open or close the door or I will simply program another micro to emulate the one that is there ... I have the time, no money, but retired.
Again thanks for the reply. Vic