RF Interference? - Help me FIRED Enginerds

[FLSUnFIRE]

For several weeks my garage door opener would not open with the transmitter in my car and I would have to get out and open using the keypad (wireless as well and has always worked...so far but getting nervous). I tried using the regular remote from the car as well when it is acting up (getting worse, almost 100% failure now) and it also doesn't work but the keypad still works. Once I pull into the garage, the car button and the remote work to close the door (and to open and close it when I depart without fail... so far) so they are still synced with the opener.


I thought I read somewhere that a dying capacitor can cause RF interference but I can't find any good references. Is it a good theory? I don't want to waste ~$20 to swap the capacitor if the theory is bad. I notice no hesitation to open other than the buttons not working so it seems the capacitor is still doing it's job.


Appreciate your theories and suggestions! Thanks!


FLSunFIRE

 

[Time2]

I can only through out a few ideas.
The bad capacitor idea is lacking, there are many capacitors in the garage door opener. I have never seen that as a problem.

1) make sure the remote battery is good.
2) is the antenna visible hanging down from the motor unit?
If not fix that.
3) Interference caused by some external device could reduce the receiver sensitivity. You could try turning of all circuit breakers in your house except for the one the garage door opener is on. Then test to see if the remote works better, if it does, turn on breakers one at a time until the remote stops working properly. Then figure what is on the last breaker that could cause interference. I read one story about a clock radio causing the remote to malfunction.

Here are videos that have some problems with theory as I know it, (not cut to frequency, running along an iron bar) but they shows success, so...
https://tinyurl.com/35t9vfam

I found many videos presenting the same idea, so it seems to work.
Hope that helps.

 

[FLSUnFIRE]

Thanks Time2, I like that idea. I was skeptical of the capacitor theory but it would be an easy fix if so.



I don't think it is an issue with anything I have causing interference but I'll try some troubleshooting. The intermittency of the issue (worked for me when I just returned home now) makes disconnecting things to check a bit challenging! Unfortunately, I am in a townhouse in a dense urban area so the airwaves are full of EME. I have pretty minimal electronics and no recent changes. I've been trying the T-Mobile 5G Gateway (do not recommend based on my experience) but this issue happens even with it unplugged.


I like the extending the antenna idea. I did already check that the antenna was not obscured but if it's as easy as adding a wire, I can do that! Just need to find the time (7 weeks till I'm FIREd and my self-love honey-do list keeps growing)!

 

[Time2]

Thanks Time2, I like that idea. I was skeptical of the capacitor theory but it would be an easy fix if so.



I don't think it is an issue with anything I have causing interference but I'll try some troubleshooting. The intermittency of the issue (worked for me when I just returned home now) makes disconnecting things to check a bit challenging! Unfortunately, I am in a townhouse in a dense urban area so the airwaves are full of EME. I have pretty minimal electronics and no recent changes. I've been trying the T-Mobile 5G Gateway (do not recommend based on my experience) but this issue happens even with it unplugged.


I like the extending the antenna idea. I did already check that the antenna was not obscured but if it's as easy as adding a wire, I can do that! Just need to find the time (7 weeks till I'm FIREd and my self-love honey-do list keeps growing)!

One thing I didn't mention before because I could not locate an example. There is an antenna called a yagi. The simplest uses the antenna and puts a wire behind that which is slightly longer (Reflector) and one in front (director) that is slightly shorter.
I have seen but cannot now find, where some one put up just the Reflector and it help them. This is more complicated, because the length is critical as well as the spacing from the antenna.

 

[Ole Red 29]

instructions that came with my garage door opener mentioned not to use an LED bulb in the opener due to interference with the remote. Have you happened to replace the bulb with and LED lately?

 

[OldShooter]

The obvious: Fresh battery in your remote?

The external interference theory is attractive. The closer your transmitter to the receiver, the stronger its signal will be relative to external signals. Hence the keypad works and the remote works in the garage.

What you have heard about capacitors probably referred to the power company's power factor correction capacitors installed on some poles. Possibly the power company would be willing to come out with radio equipment that would identify such a problem. Otherwise, there is nothing you can do. Ham radio guys run into this from time to time, so some Google Fu might be educational for you.

Adding wire to the antenna might work, but don't run it along something metal. That will interfere with reception. Run it along a rafter or just hang it in free air. More is not better; more than is necessary just makes your opener vulnerable to other radio signals or even other openers that happen to be on the same code. Find a length that works (if antenna extension works at all for you) then go no longer.

Opener transmitters are cheap. If you're still stuck, buy a new one, program the opener to it, and see if that solves the problem.

 

[FLSUnFIRE]

The obvious: Fresh battery in your remote?

The external interference theory is attractive. The closer your transmitter to the receiver, the stronger its signal will be relative to external signals. Hence the keypad works and the remote works in the garage.

What you have heard about capacitors probably referred to the power company's power factor correction capacitors installed on some poles. Possibly the power company would be willing to come out with radio equipment that would identify such a problem. Otherwise, there is nothing you can do. Ham radio guys run into this from time to time, so some Google Fu might be educational for you.

Adding wire to the antenna might work, but don't run it along something metal. That will interfere with reception. Run it along a rafter or just hang it in free air. More is not better; more than is necessary just makes your opener vulnerable to other radio signals or even other openers that happen to be on the same code. Find a length that works (if antenna extension works at all for you) then go no longer.

Opener transmitters are cheap. If you're still stuck, buy a new one, program the opener to it, and see if that solves the problem.

The remotes are 2019 vintage and barely used and the programmed car button has a pretty good 12-14V supply. It is two transmitters that don't work outside and the keypad that does. Even the remote just outside the door didn't work.


There is definitely a change somewhere as they were reliable until recently. Thanks for the additional ideas!

 

[CRLLS]

The obvious: Fresh battery in your remote?

The external interference theory is attractive. The closer your transmitter to the receiver, the stronger its signal will be relative to external signals. Hence the keypad works and the remote works in the garage.

What you have heard about capacitors probably referred to the power company's power factor correction capacitors installed on some poles. Possibly the power company would be willing to come out with radio equipment that would identify such a problem. Otherwise, there is nothing you can do. Ham radio guys run into this from time to time, so some Google Fu might be educational for you.

Adding wire to the antenna might work, but don't run it along something metal. That will interfere with reception. Run it along a rafter or just hang it in free air. More is not better; more than is necessary just makes your opener vulnerable to other radio signals or even other openers that happen to be on the same code. Find a length that works (if antenna extension works at all for you) then go no longer.

Opener transmitters are cheap. If you're still stuck, buy a new one, program the opener to it, and see if that solves the problem.

Somehow, my outside wireless keypad operates differently from the other remotes. If I activate the "lock" feature on my inside wall switch, the keypad will still open the door while the other RF remotes will not. I don't know if this is standard operation of all systems or not. Mine is an older Chamberlain/Lift Master opener

 

[rpguy4]

Is your car fairly new, and/or maybe have it's own Wifi hot spot ? Wondering if somehow the car is causing the interference.

 

[FLSUnFIRE]

Somehow, my outside wireless keypad operates differently from the other remotes. If I activate the "lock" feature on my inside wall switch, the keypad will still open the door while the other RF remotes will not. I don't know if this is standard operation of all systems or not. Mine is an older Chamberlain/Lift Master opener

Will test it out in a bit, hopefully that easy!

 

[Jerry1]

Did you just put in new LED lights into the head unit? I did that and had exactly what you described. Then I found that interference from the LED’s is a thing and they make a bulb that is for garage openers. Bought them and it worked. You could test this by just removing your bulbs if they are LED’s.

 

[FLSUnFIRE]

Checked the lock function and that was not it. Interesting weirdness, when I left yesterday neither the car's built in transmitter or the handheld remote would work from inside the garage to open the door (used the wired inside) but once open, they did close the door from outside.



When I returned, neither would open the door and I tried the handheld from the same spot the keypad is mounted so I used the keypad and it worked. Immediately after the door started to move after using the keypad (door just cracked), I used the handheld remote to stop the door, close the door, and reopen it (from the same location that the remote didn't work from seconds ago). Somehow activating the door makes all remotes work well for a period of time. (that's when the light comes on, they don't work when the light is off! -a CFL) The greater factor seems to be having recently used the opener for all to work and not the location of the transmitter (inside or outside -although inside works better). It seems like using the door eliminates the interference for a period of time... almost lending credence to the capacitor theory (when fully charged it causes interference?) or some other component within the opener itself.

 

[target2019]

When I have had problems with remote opener(s) the first fix is to change the battery. I don't have a button powered by auto voltage, but connections need to be checked, of course.

Inside each remote is a contact switch, so they need to be looked at.

Another item to look into is the actual scrambling which goes on to provide some security. I would reset the opener, and redo all the remotes, and use a new PIN.

In addition to LED producing some interference, you could have another device on that leg causing problems.

EDIT: Try an incandescent bulb instead of CFL.

 

[marko]

Had a similar problem. Turned out to be that once I had programmed the door into my built-in button in the car, I stored the original remote in a junk drawer. Somehow, the button on the original remote got pushed to 'on'.

 

[ERD50]

...

EDIT: Try an incandescent bulb instead of CFL.

... Somehow activating the door makes all remotes work well for a period of time. (that's when the light comes on, they don't work when the light is off! -a CFL) ...

Weird. Doesn't seem to point to CFL/LED interference.

So weird, that I'm going to suggest that this was just co-incidence. When tracking down an intermittent problem, it is easy to get fooled into seeing cause/effect that isn't there. It is human nature to look for patterns.

For intermittent problems, get back to basics. I'd put in an incandescent just to eliminate that theory. I think the suggestions for fresh batteries, and reset and re-learn everything is a good start.

I see no basis for blaming a "capacitor", any more than I'd think the problem was with an inductor or a resistor. Let the process lead you to the problem, don't make assumptions until you have some evidence to point you there.

Could be it's just plain "broken".


Hmm,m don't know if this was mentioned, do you have a fridge or freezer in the garage? Those can kick out electrical noise, and relative to opening/closing the garage door, would be random.

-ERD50

 

[cathy63]

Are any of your neighbors having problems with their garage doors? Could be something outside.

 

[latexman]

This is probably not your problem, but . . .

My daughter moved out on her own, and gave her garage remote to my son, who is home from college for the summer. She said it never worked, and son confirmed it did not work. I immediately assumed it was going to need a new battery, so I opened it up to see what type it needed. Interestingly, when I removed the one screw holding the remote together, I must have touched the button or something, and the garage door started opening! Hmmmm, once fully open, I noticed the battery was pushed far to one side in it's area and the contact at the far end was touching the edge of the battery and cantilevered off of the battery terminal end. So, I took the battery out and bent both contacts so the battery would be centered and the contacts hit the terminals with both sides having about equal spacing. I popped the same battery back in, and it's been working ever since.

 

[Out of Steam]

instructions that came with my garage door opener mentioned not to use an LED bulb in the opener due to interference with the remote. Have you happened to replace the bulb with and LED lately?

I have an older opener in my garage and was wondering about this. I'll stick with the existing incandescents.

 

[ProspectiveBum]

I second (third? fourth?) the advice to try an incandescent bulb first to rule that out. I had the exact behavior you describe, and it was due to a bulb putting out interference. After installing one meant for garage door openers, no issues.

 

[Scrapr]

Try an incandescent bulb instead of CFL.

My MIL has a basement full. If OP need a hookup holla back

Since this is black market Bitcoin only

 

[ProspectiveBum]

I have an older opener in my garage and was wondering about this. I'll stick with the existing incandescents.

FWIW, I installed an LED bulb meant for garage door openers (no interference). So far it’s working perfectly, and is significantly brighter than the incandescent bulbs we were using. The incandescents never lasted that long due to the vibration of the opener.

 

[Out of Steam]

I'll keep an eye out for them. Would like some more light there.

 

[Time2]

FWIW, I installed an LED bulb meant for garage door openers (no interference). So far it’s working perfectly, and is significantly brighter than the incandescent bulbs we were using. The incandescents never lasted that long due to the vibration of the opener.

You might mention the brand. Different manufacturers bulbs will have a different amplitude of noise and also a difference frequency spectrum, that may cause the interference.

 

[FLSUnFIRE]

Haven't gotten back to do more detailed troubleshooting but recently it's been working pretty reliably again - thinking it's some external interference that went away. Hopefully the gremlin is gone...

 

[REWahoo]

Late to this thread.

Here's a likely suspect: Homeland security vs. garage door openers

A secretive Air Force facility in Colorado Springs tested a radio frequency this past week that it would use to communicate with first responders in the event of a homeland security threat. But the frequency also controls an estimated 50 million garage door openers, and hundreds of residents in the area found that theirs had suddenly stopped working.

The same thing happened in San Antonio when the NSA opened a new facility

In 2010, residents who lived near the facility complained that their garage doors were randomly opening. The NSA issued a statement acknowledging that an antenna it was using interfered with garage door openers.