LG G4 Knock On stopped working

[Wingerr]

Seems that recently the knock on mode of the G4 doesn't respond and I have always been on the phone using the power button on the back. A friend also noticed the same thing on his G4 so appears to be a common issue.
Any way to find out why it's not working?
When the screen is on, double tap will turn it off every time so it doesn't seem to be a screen hardware response issue.

 

[Wingerr]

Seems that recently the knock on mode of the G4 doesn't respond and I have always been on the phone using the power button on the back. A friend also noticed the same thing on his G4 so appears to be a common issue.
Any way to find out why it's not working?
When the screen is on, double tap will turn it off every time so it doesn't seem to be a screen hardware response issue.

That should be, I always have to wake up the phone using the rear button rather than the usual double tap. Maybe it's a feature of the latest update to save power by disabling screen monitoring while it's off-

 

[JohnnyBroccoli]

Seems that recently the knock on mode of the G4 doesn't respond and I have always been on the phone using the power button on the back. A friend also noticed the same thing on his G4 so appears to be a common issue.
Any way to find out why it's not working?
When the screen is on, double tap will turn it off every time so it doesn't seem to be a screen hardware response issue.

I'm having this issue too and it's driving me crazy. Any help would be appreciated. Like others, double tap to sleep works without a flaw but double tap to wake basically never works (same with a triple, quadruple, or infinite tap as well).

My memory could be off but I want to say it worked totally fine after the Marshmallow update (better than it had before actually). Then since I sent it in for repair due to bootloop issue, the tap to wake function has become utterly useless.

You're ******* killing me, LG!

 

[Wingerr]

It's mostly a hassle when I have it sitting on the table and it times out, so I have to pick it up to turn on instead of doing the quick tap-tap to wake it.

 

[abosch999]

Same problem here. Problem started a week ago... Worked perfect before. I first noticed it after a "phone too hot while charging" warning.

 

[Wingerr]

Same problem here. Problem started a week ago... Worked perfect before. I first noticed it after a "phone too hot while charging" warning.

Tried all sorts of things I found in posts regarding this, including a suggestion from LG to do a factory reset, but it's still not working for me.
It sometimes wakes up after multiple double tap entries, once it actually woke up 30 seconds after I set it down on the table after I stopped trying, strangely enough.
LG service said it may require sending it back to them for their technicians to inspect and repair, but that's too much of an interruption to go through for this, and it doesn't seem like it could be a hardware problem since the screen works fine when it's on. I wonder if this develops on most of the G4 phones in use or just a few.

 

[abosch999]

I tend to think it is a problem with the proximity sensor and the feature that keeps the phone turning on in your pocket. Screen and double tap work perfect when screen is on.

 

[snedecor]

I have no screen protector, nor do I have a case. Knock on has stopped working. Knock off still works very reliably, but Knock on does not work.

Don't think it's an issue with the proximity sensor. I've tried it on several calls, and the screen reliably dims when I get close to my ear, and lights up as I lower the phone.

Any ideas, anyone? Someone has already stated that a full factory reset didn't help...

 

[snedecor]

I just found out something that may help others! I just found out that I had battery saver enabled. I guess that disables the sensor that detects the knock on. I disabled the battery saver, and knock-on is working again! I don't remember seeing this in the manual, but, its good to know...

 

[stelios ch]

I have this issue the last 2 or 3 months.
It started doing this every so and while until the last 2 weeks it doing it very often almost every time.
I notice 1 thing. If you hide the proximity sensor for a few seconds and then release and immediately double tab the screen will come on.

I have change so many roms to test but nothing, i download many apps that calibrate the sensor. Nothing..

I follow the instructions how to calibrate the sensor using stock lg g4 rom and hidden menu device test mt sensor test. Nothing!!!!
The proximity sensor test return 125 -130 value while i read that normally should be of value 220 +

I try all the combinations to sort this out with out any success.

The double tab to sleep works fine. But to turn it on is the problem.

Is not a software issue. Either is proximity sensor or something wrong with the screen.

Those who say you need to clean the proximity sensor it's ridiculous. I have spend 1 week for this


Now i have install the stock rom and i plan to take it back for service(it's still under warranty) otherwise i don't think it's worth to fix it (if need to replace the screen probably will cost you 70 tob100 euros not say more) you can find this device for new in ebay for approximately 135 euros.

 

[eworkflow]

LG G4 might be one of the most underrated workhorses. My knock/wakeup code does not work either but, to my surprise, even with the knock code disabled, I can wake up my G4 with a long touch (~3sec) at a certain location of the 1st (top left) quadrant which seems to be left and below the quadrant's center. Double-tap to put it back to sleep works normally.