# Garage Door Safety Beam



## Rockyd (Apr 22, 2007)

Did you do the 101's of cleaning both the receiver, and the tranmitter, with a damp cloth first before "upscaling" the trouble?

Biggest problems of all, can be no problem at all.


----------



## swimmer (Mar 19, 2011)

Rockyd said:


> Did you do the 101's of cleaning both the receiver, and the tranmitter, with a damp cloth first before "upscaling" the trouble?
> 
> Biggest problems of all, can be no problem at all.


Yes, I cleaned the RX and TX as you said. I took some amp and volt measurements and I know I have continuity between RX, TX and motor control board.

Beam blocked RX: 33.6VAC, 0.14mA
Beam unblocked: RX: 27.5VAC, 5.87mA

So my guess is that it's the motor control board.


----------



## HARRY304E (Sep 15, 2010)

swimmer said:


> My garage door is behaving as if something is breaking the beam between the transmitter and the receiver. However, the receiver is getting the beam as evidenced by the LED which is lit unless I block the path with my hand. What does the beam receiver send to the motor controller. Is it DC? If yes then what voltage?
> 
> Thanks


Check your batterys in your transmitter as well...


----------



## swimmer (Mar 19, 2011)

Rockyd said:


> Did you do the 101's of cleaning both the receiver, and the tranmitter, with a damp cloth first before "upscaling" the trouble?
> 
> Biggest problems of all, can be no problem at all.


Well this is embarrassing. I cleaned the TX and RX windows a little more vigorously and it worked. I then made some measurements to compare the broken mode to the working mode. I reconnected (had an ammeter in series) and then had the same problem. I cleaned again and now it works again. I wonder for how long?
During broken mode, I measured AC only but the second time around I measured both AC and DC found that there is significant DC.


----------



## swimmer (Mar 19, 2011)

*Ongoing Garage Door Opener Electronics Troubleshooting*



swimmer said:


> Well this is embarrassing. I cleaned the TX and RX windows a little more vigorously and it worked. I then made some measurements to compare the broken mode to the working mode. I reconnected (had an ammeter in series) and then had the same problem. I cleaned again and now it works again. I wonder for how long?
> During broken mode, I measured AC only but the second time around I measured both AC and DC found that there is significant DC.


The unit failed again shortly after I cleaned it for the second time. I disconnected both the RX and TX cables and connected in a resistor box. I dialed the box in to get the AC current I'd seen in the working mode but could not fool the control control board. I also tried a neighbor's control board and symptoms remained.

I had some door bell wire handy so I replaced the RX cable and it has worked consistently for a day now.

What is the RX unit sending to the control board? 
I'd like to know how to bypass so that I can quickly diagnose whether control board or RX / TX problem. I figure everyone in my housing tract should be getting this problem about now.


----------



## Jlarson (Jun 28, 2009)

It's nothing you can replicate with just a resistance or contact closure.


----------



## swimmer (Mar 19, 2011)

Jlarson said:


> It's nothing you can replicate with just a resistance or contact closure.


Do you know where I can get more info on this? Maybe I'll just end up buying RX and TX for troubleshooting if my neighbors start coming to me with this problem. Haven't spent a dime yet though and I want to stay on this roll.


----------



## Jlarson (Jun 28, 2009)

You're gonna need to put a o-scope on it to see what the signal is.


----------



## AFOREMA1 (Nov 23, 2009)

RedLiz75 said:


> You can find the answer to your question at electricians job talk dot com!


Hey redliz do you own that site? Seems you throw this exact sentence out in just about every thread your in.

And why do you spell it out trying to keep this sites moss from catching on too you?


----------



## gold (Feb 15, 2008)

AFOREMA1 said:


> Hey redliz do you own that site? Seems you throw this exact sentence out in just about every thread your in.
> 
> And why do you spell it out trying to keep this sites moss from catching on too you?


Let it go. I don't think she is part of this forum any longer.


----------



## HARRY304E (Sep 15, 2010)

swimmer said:


> Do you know where I can get more info on this? Maybe I'll just end up buying RX and TX for troubleshooting if my neighbors start coming to me with this problem. Haven't spent a dime yet though and I want to stay on this roll.



This might help..


http://www.1stdooropeners.com/lineartroubleshoot.htm


----------

