Database Users

Knock knock not as responsive waking up...

Sometimes I have to knock knock twice in a row to turn on the device. It works well turning off, but on half of the times it won't turn on. Gotta do it twice. Anyone else encounter this?
Sent from my LG-D803 using Tapatalk 4

Brava27 said:
Sometimes I have to knock knock twice in a row to turn on the device. It works well turning off, but on half of the times it won't turn on. Gotta do it twice. Anyone else encounter this?
Sent from my LG-D803 using Tapatalk 4
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I do not have that issue, but I have read in a few posts that it can be dependent on where you are knocking on the screen.

hd-renegade said:
I do not have that issue, but I have read in a few posts that it can be dependent on where you are knocking on the screen.
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Yes! Excellent advice
Sent from my LG-D803 using Tapatalk 4

Brava27 said:
Yes! Excellent advice
Sent from my LG-D803 using Tapatalk 4
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I think the biggest issue is knock speed.... mine works damn near 100% when I slowed down some, and knock slower like it showes at the end of the G2 commercials....

I think it's partially related to the proximity sensor. There are times when I can't get the knock on to work at all and when I hit the power button the screen shuts right back off.
Usually a few swipes over the sensor makes it work again. Sometimes I'll go in and turn the Knock On gesture off and back on and then it seems to work great for a while too.

csmith8507 said:
I think it's partially related to the proximity sensor. There are times when I can't get the knock on to work at all and when I hit the power button the screen shuts right back off.
Usually a few swipes over the sensor makes it work again. Sometimes I'll go in and turn the Knock On gesture off and back on and then it seems to work great for a while too.
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This is my exact problem. The phone just decides it doesn't want to wake up with knock-on...but after I press the power button, it only turns on for half a second and it's out again. I never tried swiping over the sensor, but hopefully it works because it's mighty annoying when it does it during a call!
I wonder if there's a fix for this?

canecbr600 said:
I think the biggest issue is knock speed.... mine works damn near 100% when I slowed down some, and knock slower like it showes at the end of the G2 commercials....
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this, if you are trying to do it like you did on the nokia n9 or nokia 8800 then it won't work
slow deliberate knocks are the only way
waiting on the g2 to arrive, but on my review unit, knock knock wouldn't respond correctly if i left the phone on the table, but if i picked it up, it would work nothing scientific here just an experience of one person and one prototype

I had the same issue... What fixed it is: 1. I found that the screen protector was hindering it somewhat. 2. Go to settings->display->screen-off effect-> and change it to simple. This REALLY seemed to help. Let us know!

in_dmand said:
I had the same issue... What fixed it is: 1. I found that the screen protector was hindering it somewhat. 2. Go to settings->display->screen-off effect-> and change it to simple. This REALLY seemed to help. Let us know!
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I did notice it does seem to behave better when set to simple for the screen off animation.
My screen protector does have a cutout around the sensors. Keeping the sensor area clean enough to qualify as having OCD does seem to make it work properly the first time, every time. Maybe it's overly sensitive?
Edit: Scratch that. 30 seconds later it's behaving erratically again. Maybe it's not the fact that it's clean, but the swiping over the sensor that temporarily resolves it.

it also seems to work much better when knocking at the top of the screen where the statusbar would be.

So I ended up swapping the phone out over the weekend for a new one and now everything seems to work just fine. Seems to indicate that it's not a software problem, but rather a hardware issue with the proximity sensor.

Guys if your covering the sensors when turing the device screen on it will turn right back of on you. It's a feature LG implemented so the device wouldnt wake up in your pockets. Don't cover the sensors.
Need a little example? Grab your phone and cover the sensors and knock knock knock.You can knock till the cows come home but it will not turn on. Same thing goes for the power button but its a little delayed and will turn the screen on for half a sec and turn right back off. Practice not to do this because your phone isn't broken. There is actually a thread on this deep in the forums somewhere but its been forgotten now.

Walter21026 said:
Guys if your covering the sensors when turing the device screen on it will turn right back of on you. It's a feature LG implemented so the device wouldnt wake up in your pockets. Don't cover the sensors.
Need a little example? Grab your phone and cover the sensors and knock knock knock.You can knock till the cows come home but it will not turn on. Same thing goes for the power button but its a little delayed and will turn the screen on for half a sec and turn right back off. Practice not to do this because your phone isn't broken. There is actually a thread on this deep in the forums somewhere but its been forgotten now.
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This is true however there are indications of problems with the proximity sensor as well. Some of the devices are behaving as if tree sensor is covered even when it's not.

Walter21026 said:
Guys if your covering the sensors when turing the device screen on it will turn right back of on you. It's a feature LG implemented so the device wouldnt wake up in your pockets. Don't cover the sensors.
Need a little example? Grab your phone and cover the sensors and knock knock knock.You can knock till the cows come home but it will not turn on. Same thing goes for the power button but its a little delayed and will turn the screen on for half a sec and turn right back off. Practice not to do this because your phone isn't broken. There is actually a thread on this deep in the forums somewhere but its been forgotten now.
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Thanks for this.. Very insightful.. I tried it immediately LOL

I had the same issue. I have no case or screen protector on, and was not covering the sensor when trying to wake the phone. For some reason though, knocking wouldn't wake the phone, and pressing the power button would only turn the screen on for a few seconds. I want even given enough time to get past the unlock screen. I went into the store and they are sending me a replacement that should come in later this week. It doesn't happen all the time. It is much more noticeable after receiving a call though.
Sent from my VS980 4G using Tapatalk

Definitely is dependent on the proximity sensor. If i just have my thumb on the edge of the phone by the sensor it will display this problem. Even with my finger a half to one inch above it will do this. I will be paying close attention to the proximity sensor from now on when it doesn't work. Still have a few days to return and thought i had an issue but maybe not.
Sent from my VS980 4G using xda app-developers app

sometimes its also greasy fingers, at least in my case, rarely though

As long as you tap twice the same place it's working fine. If distance between first and second tap is greater than 1 - 1.5 cm it won't work.

Got the same problem on my d802...when i left the phone on my table for 2-3min it wont wake up on first knock knock even power key wake it up for 1sec after auto turn off again....even with no screen protector....i noticed that sometimes there is a delay about 5-10sec after knock knock and screen turns on....other thing i noticed when i knock on immediently after turning off it works 100%....BUT i also noticed when i knock on after a while it turns on and i can unlock got vibration and sound of the unlock but i cant see anything. Screen looks like its off but when i look closely i can hardly see widgets and when i set effect to tv out i can see the effect by pressing the power button...when i press the power button again screen turns on like normal...i noticed sometimes on a rerboot the lg bootlogo disapears the led is working an showing all colors but the boot animation is gone like the screen is off at the bootup...dont know why after the bootup the pin lock screen is showing up normal....sorry for my english^^

Problems after replacing screen, LCD and frame

I have replaced the screen, LCD and frame on my VS980 due to dead sections of the screen. There were no problems swapping everything over to the new frame. The phone seemed to be working perfectly until I went into a dark room. When I am in a room with little to no light knock on does not work and if I press the power button the screen times out while I am swiping the home screen. Which component will cause this problem? I double checked each piece before reassembly and everything appeared to be properly installed.

Have you tried the motion sensor calibration? For me i press the power and volume down button quickly and it unlocks. Have you update the touch firmware?

I did the motion sensor calibration and it didn't help. the dialer codes I have found for the vs980 don't get me into the service menu.

I dont know for sure but i think its the hardware problem as in replacing the new LCD and all, but ya that be expensive to buy new ones just after buying a new one. If it still have warranty maybe replacing it perhaps. If the service menu dont work, i dunno.

Your proximity sensor may not be plugged in all the way.
How does the phone work while making a call?
Test it first. If the screen stays on during a call while the phone is held to your face, open it back up and double check all connections.
Unplug and replug the screen, digitizer connections, selfie cam and proxy sensor connections then test again.

The proximity sensor which is top left when looking at the front display. Smush and/or rub with your finger, then try to unlock again. I have to do this frequently.
Sent from my LG-LS980 using Tapatalk

Always on 2nd screen in the dark issue ??

I bought a used V20 with a defective screen. I change it, everything work for fine, but i notice a strange behaviour with the second screen.
The second screen is always on and i can unlock it by only touching the finger print sensor. BUT at night (or in the dark), the second screen turn off and i need to press 2 times on the power button to wake the phone.
The Knock On feature doesn't work too in the dark.
The light sensor seems to work correctly.
I would love to post a video but i can't......
This is an issue or it is normal ??
Thanks for your help !

Sounds like Doze.

I don't find anything related to Doze or "standby" about this screen.

check "daily timeout" on Show when main screen off. Seem u turn this function on at night
David_26 said:
I bought a used V20 with a defective screen. I change it, everything work for fine, but i notice a strange behaviour with the second screen.
The second screen is always on and i can unlock it by only touching the finger print sensor. BUT at night (or in the dark), the second screen turn off and i need to press 2 times on the power button to wake the phone.
The Knock On feature doesn't work too in the dark.
The light sensor seems to work correctly.
I would love to post a video but i can't......
This is an issue or it is normal ??
Thanks for your help !
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thophan1975 said:
check "daily timeout" on Show when main screen off. Seem u turn this function on at night
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Don't seems to change anything
Could it me the last security update ??
I reset the phone today and same "issue"

David_26 said:
Don't seems to change anything
Could it me the last security update ??
I reset the phone today and same "issue"
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Sounds like there is an issue with the proximity sensor (not light sensor).
It's setup to turn the second screen off as well as disable knock on if the phone is in your pocket. Even during daylight hours if you put your finger within an inch of the sensor when the main screen is off, it should trigger it.
It seems your sensor may just be messed up.

David_26 said:
Don't seems to change anything
Could it me the last security update ??
I reset the phone today and same "issue"
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There are a few apps on the play store you can try to fix it if you are rooted. You could also try a sensor app to see if the proximity sensor is showing feedback properly although you might need to be rooted for the apps to show the proximity sensor properly (not sure). My note 4 had a hardware test in the service menu not sure how to do it on V20 though.

Same Issue
Edit: Resolved the issue. Please read this post. There is a small rubber gasket-type thing that sits in the hole of the phone's frame where the proximity sensor is positioned. That rubber gasket was not included with my replacement screen. I pulled the rubber piece out of my original, broken screen, and installed it into my replacement screen. I am no longer having issues with the phone in the dark.
I am experiencing the same issue. I have a T-Mobile LG v20 (H918) and I cracked the screen last week. I ordered a replacement LCD assembly and installed it myself. Everything works fine during the day or in a well lit room, but at night, in a dark room, I experience all of the issues you are reporting. I am finding other posts online with our same issue, but as of yet, no resolution.
Even though the second screen is set to always be on, at night, in a dark room, it turns off almost immediately after locking the phone. It is almost as if the phone is in a "deep sleep" or something, because the following also occurs:
Knock On will not wake the phone
Fingerprint sensor will not wake the phone
Even connecting to the phone via AirDroid / AirMirror the phone doesn't wake
Need to press the power button multiple times to wake phone
Providing a light source immediately turns on second screen and resolves all issues

When the main screen is off, second screen works but is... invisible??

I want my second screen to be on when the main screen is off. Second screen works fine when main screen is on. When I turn off the main screen, the second screen changes for a split second (you know how it changes to signature/time?) and then goes black. BUT it still works. From memory, I can swipe to quick toggles and turn on/off my flashlight and it works. But the second screen stays black.
This started after I replaced my cracked screen. After swapping it with a replacement, I was having a bunch of issues with the proximity sensor (second screen off when main is off, knock on wouldn't work, fingerprint wouldn't work, sensor app always said 0cm). I fixed these by moving over the little rubber gasket from my old screen, but the second screen still doesn’t work.
Second screen daily timeout is disabled. I wiped dalvik/cache from recovery. Rebooted multiple times. Opened it back up and reconnected the display ribbon cable. Tested the display and sensors from the hidden service menu.
Any advice?? I'd like to troubleshoot further before doing a hard reset (I have so many mods installed lol). This second screen is why I haven't upgraded the phone yet...

You forgot to put the rubber gasket for the proximity sensor back in. Without it, you'll see exactly the problems you are now. Search eBay for LG V20 Rubber Gasket Holder and you'll see the part I'm talking about. If you put it back in it will fix these issues. It's a common problem with the LG V20 screen repair.
dwrdbg said:
I want my second screen to be on when the main screen is off. Second screen works fine when main screen is on. When I turn off the main screen, the second screen changes for a split second (you know how it changes to signature/time?) and then goes black. BUT it still works. From memory, I can swipe to quick toggles and turn on/off my flashlight and it works. But the second screen stays black.
This started after I replaced my cracked screen. After swapping it with a replacement, I was having a bunch of issues with the proximity sensor (second screen off when main is off, knock on wouldn't work, fingerprint wouldn't work, sensor app always said 0cm). I fixed these by moving over the little rubber gasket from my old screen, but the second screen still doesn’t work.
Second screen daily timeout is disabled. I wiped dalvik/cache from recovery. Rebooted multiple times. Opened it back up and reconnected the display ribbon cable. Tested the display and sensors from the hidden service menu.
Any advice?? I'd like to troubleshoot further before doing a hard reset (I have so many mods installed lol). This second screen is why I haven't upgraded the phone yet...
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LG V35 double tap doesn't unlock screen, always on display doesn't work too - Help!

Hey guys, just got LG V35 updated it to android Pie, everything seemed fine, but i can't normally unlock phone. On main screen i can double tap and it locks, however double tapping again, doesn't unlock phone, as if screen froze. Also fingerprint button doesn't work either, i mean i need to press it twice slowly and only then screen turns on and shows lock screen, always on display also doesn't work. After simple restart those features work, but after a minute, same thing happening again. Also noticed, that if someone calls, screen is also unresponsive. Got phone couple days ago. Any solution ?

Tadziunia said:
Hey guys, just got LG V35 updated it to android Pie, everything seemed fine, but i can't normally unlock phone. On main screen i can double tap and it locks, however double tapping again, doesn't unlock phone, as if screen froze. Also fingerprint button doesn't work either, i mean i need to press it twice slowly and only then screen turns on and shows lock screen, always on display also doesn't work. After simple restart those features work, but after a minute, same thing happening again. Also noticed, that if someone calls, screen is also unresponsive. Got phone couple days ago. Any solution ?
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i had the same issue when i got mine. i think the screen protector i installed was the issue-it only had adhesive around the the edge and started to come off. i returned that one and replaced it with another make and haven't had the "knock on/off" issue since. good luck
tom

tomdi1999 said:
i had the same issue when i got mine. i think the screen protector i installed was the issue-it only had adhesive around the the edge and started to come off. i returned that one and replaced it with another make and haven't had the "knock on/off" issue since. good luck
tom
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I agree with tomdi1999 and also have used the adhesive around the edge screen protector but they interfered with screen touch sensitivity, it is as if having a couple of fingers touching the screen permanently while trying to double tap or unlock the phone via power button. If you have any glass screen protector, try removing the screen protector and double tap again to see if it fixes the issue. If you are not wanting to remove the screen protector first and want to do some troubleshooting, try run touch screen test via the hidden menu (assuming your v35 is AT&T version) by dialing *#546368#*350# (Be warned that some options in this menu can really mess up your phone so don't go around messing with options in this menu randomly) in the phone dialer. In hidden menu select Device Test -> SAAT -> Service Menu - Manual Test -> Touch Draw Test. If, with screen protector on you are having trouble doing this test, remove the screen protector, clean the screen, and do the test again. If you still have trouble with touch screen it is probably a hardware problem or could be software problem but unlikely though. Also, place a test call to someone and slowly place your hand to cover the ear piece and proximity sensor area to see if screen goes dark. This is to check if your proximity sensor is working properly because if it is not then it could be the reason that double tap to wake is not working, although it doesn't explain why your power button is responding slowly, that points toward the phone processor being busy due to ghost touches such as due to bad screen protector or just a faulty power button (but what are the chances of having a faulty power button and double tap to wake going bad at the same time lol?).
I remember that years back on LG G4 double tap function would stop working if you had the screen replaced or sent in the phone to LG for repairs such as repair for notorious bootloop issues and it turned out that there was a small rubber piece that went around the proximity sensor that people were forgetting to put back when replacing screen or doing other repairs which basically broke the proximity sensor. Proximity sensor is suppose to disable screen wake up due to accidental double taps such as when phone is in pocket but if proximity sensor is malfunctioning it will not let phone wake even when you double tap to wake it.
If you figure out what was wrong and/or fixed your issue, please do post back so it can help others. Thanks.
Edit: If you are looking for a good screen protector try Skinomi or Armor Suit wet screen protectors. They are not glass and are a pain to put on but once you install them and let them dry, they are awesome.

It helped me thanks a million!
wouldn't think ever it was the screen protector, thought one of my apps...
I've removed it and it was back to normal.
thanks again