Light and proximity sensors are not visible (Samsung) - General Questions and Answers

Hi,
My customer brought to me a Samsung A40 after water damage. After cleaning up and replacing the screen to the original one everything looked great until the first call. It appeared that both the light sensor and the proximity one are not even visible under *#0*# menu. I can easily bypass that by switching the power off button to end the call but since then the smartphone also doesn't turn off the screen :/
I've set to turn off the screen after 15s, udpated the software, performed wipe cache and full factory reset. None of them had worked. Screen if not manually locked remains ON all the time. Can it be connected somehow to the damaged sensors? During the call screen is still blinking.
I would be gratefull for any tip in this case.
I can even root the device to just get rid of that "not turning off of the screen". Is there some app maybe to force screen lock after some time of not active?
BR

Check for moisture and/or corrosion on the ribbon cable connectors.
Water damage is unpredictable especially if the battery is not pull immediately.
The best thing to do is flush liberally with anhydrous isopropyl alcohol* and completely dry.
Salt water is always lethal... eventually.
*isopropyl or any solvent will poison LCDs, never use it near them. Use best judgment otherwise.

blackhawk said:
Check for moisture and/or corrosion on the ribbon cable connectors.
Water damage is unpredictable especially if the battery is not pull immediately.
The best thing to do is flush liberally with anhydrous isopropyl alcohol* and completely dry.
Salt water is always lethal... eventually.
*isopropyl or any solvent will poison LCDs, never use it near them. Use best judgment otherwise.
Click to expand...
Click to collapse
Thanks for the reply. I've already put the phone apart and cleaned every single pcb, connectors, cables with isopropyl in ultrasonic wash and manually with toothbrush. Left it to complete dry for about 48 hours and put it back together. Before that the phone was completely dead. Now everything is working except those 2 sensors. I don't have any datasheet to this mainboard so i don't even know what else can I measure.
Whole thing happened like 2 months ago and the customer just tried to manually lock the screen but its not always possible and he noticed that his battery is drawing pretty fast due to screen on. On the current stage I'm just looking for some workaround to force the screen sleep and remains until power button pressed.

What is funny. The screen goes to sleep after 15s when connected to charger and locks after 1 minute just like I've set in the settings...
When it is inpluged from charger screen remains awake all the time :/ Maybe that's some clue for anyone?
More tests: light sensor seems to be working correctly. It adjust brightness when covered and uncovered despite the fact that it is not visible under "sensors" in "*#0*#" menu Proximity sensor still doesn't work. When calling someone screen remains black and just flashes from time to time...
But the main problem is still with those screen always awake. It is only going to sleep when connected to PC or charger :/ No moisture visible anywhere. I've found a post with the same problem but there was visible that phone was detecting periodically USB connection when it was unplugged. In my case Samsung is not noticing anything on tray etc. It just remains awake until pressed power button or connected to charger
I will try to replace USB charging PCB and give You the feedback

Maybe contacts on a BGA chipset corroded and shorted out a logic circuit pathway.
If it's under a chipset... game over, however it may on be an accessible area. Optical aid and good light.
It's also possible the water shorted out something enough to damage a chipset.

Replacing the USB PCB did the job. Everything works correctly, screen is going to sleep. Moreover the proximity sensor has started to work correctly
We may close this topic.

For the record, you can use *#77692# for the light sensor and proximity sensor if they don't show up in *#0*#.

Related

[Q] Screen VERY Dark After Accident But NOT Black - Phone Still Usable - Need Help

Hey guys,
I have a Droid Incredible 2 that I dropped in a cup of water for a small amount of time. I let it dry, and when I turned it on the screen was very dark. There was still an image, but it was almost impossible to see. The phone still works, it will text and call, but it is almost impossible to see things.
So, I replaced the screen with a new unit, confidant that it was the problem. But, of course, that did not fix it. I am out of ideas, so I am hoping someone here can chime in! (My question is what else could be the cause?)
Thanks for any help!
If your phone is in uder warranty replace it
Sent from my GT-S5360 using xda app-developers app
Did you replace the actual LCD screen or just the touch panel (piece of glass on the front of the phone)?
If you did replace the LCD that sounds like the backlight isn't turning on. This could be for a variety of reasons, but probably something that powers the backlight on the phone's circuit board got damaged by the water since the light itself should be part of the screen assembly. You could try removing the battery and leaving it in a bag of dry rice or those dessicant packets (things that say "Silica Gel - Do Not Eat") that come in shoes, electronics, etc. for a few days and see if maybe it's just some more water that needs to dry out, but if that doesn't help you're probably looking at a circuit board replacement or buying a new phone like andromaki suggested. It also wouldn't hurt to take the phone apart again and check to make sure you plugged in all the cables that come out of the screen and none are upside down/not in the connector all the way.
* Yes, I'm specifying dry rice for a reason. I once advised someone to stick a phone that got dropped in the sink into a container with some rice, and they put it in some leftover fried rice from Chinese take out, which did not help matters.
I agree with lroop. "Very dark" sounds like the backlight or backlight inverter (power supply) might be bad. I would assume that the backlight and inverter would all be built into the display, but that may not be the case. If the inverter is separate from the LCD and it has gone bad then switching the display would not fix the problem.

Water Damage Boots To Black Screen

So I've had this phone water damaged. I left it in rice in a very hot room for maybe 4 months. It boots into recovery and download mode fine and the screen works well. But when i boot it normally after flashing fresh Stock Firmware (It didn't boot before just stuck on splash). I plug phone into charge and the Samsung charger plug sound plays. That means its actually loaded into Android. Any ideas how to fix this?
I thought of replacing the LCD but since Download and Recovery shows up fine then it shouldn't be it?
You need to pull the battery asap after water exposure. The phone needed to come apart right away. Perhaps the mobo has conformal coating but the connectors do not have any protection.
You need to pull the whole thing apart, inspect and dry it completely.
Its long term prospects aren't good.
blackhawk said:
You need to pull the battery asap after water exposure. The phone needed to come apart right away. Perhaps the mobo has conformal coating but the connectors do not have any protection.
You need to pull the whole thing apart, inspect and dry it completely.
Its long term prospects aren't good.
Click to expand...
Click to collapse
It's been dried for a whole 2 or 3 months in rice and a hot room. Phone boots fine now but only to Download mode or Recovery mode. Screen doesn't work past splashscreen when booting
blackhawk said:
You need to pull the battery asap after water exposure. The phone needed to come apart right away. Perhaps the mobo has conformal coating but the connectors do not have any protection.
You need to pull the whole thing apart, inspect and dry it completely.
Its long term prospects aren't good.
Click to expand...
Click to collapse
It's been a few months after it's been water damaged I havent run it since BTW
Hamisxa said:
It's been a few months after it's been water damaged I havent run it since BTW
Click to expand...
Click to collapse
You mean you tore it down right away?
blackhawk said:
You mean you tore it down right away?
Click to expand...
Click to collapse
No I mean i tossed it in rice for 2 months in a very hot room and left it there. I tried to take the back off but it started crackling so I didn't try to take it further. I thought the battery might blow up.
Hamisxa said:
No I mean i tossed it in rice for 2 months in a very hot room and left it there. I tried to take the back off but it started crackling so I didn't try to take it further. I thought the battery might blow up.
Click to expand...
Click to collapse
The battery won't blow up unless you get it really hot. You can't leave water in these devices at all, every minute counts especially if it has a battery.
Sorry but the rice method doesn't cut it.
My Buds case fell in my coffee and sunk to the bottom. Fished it out and tore it apart on the spot. Flushed with RO water, then rinsed with anhydrous isopropyl alcohol using centrifugal force to get as much of the alcohol off (no compressed air in the car) then let it dry.
Amazingly it still is working a year latter; I got lucky, but I was also acted fast and did the right things.
Aside from nose diving it into my full cup of coffee.
I wouldn't invest to much money into this device. Water damaged electronics are insidiously unpredictable and there's no time limit to when it will fail again even if you do manage to get it working.
Dirt minimum; take it apart and carefully inspect it. Pull the micro ribbon connectors and inspect the contacts. Make sure they're completely dry.
Anhydrous isopropyl alcohol (99%) can be used to displaced water. Be careful around LCDs if present as it can poison the liquid crystals.
Exactly the same story with a smartphone at work. The phone starts into recovery with no prolem, the display is working fine. But when I start the system it only shows me the "Samsung Galaxy A51" lettering, "Secured by Knox" and the "Powered by Android". After booting the display remains black but the device gives a feedback when pressing the volume up/down buttons.
Is there any way to reinstall the whole OS? Or maybe authorize the Fingerprint of my PC to check if there's any display output via scrcpy?
Folsense said:
Exactly the same story with a smartphone at work. The phone starts into recovery with no prolem, the display is working fine. But when I start the system it only shows me the "Samsung Galaxy A51" lettering, "Secured by Knox" and the "Powered by Android". After booting the display remains black but the device gives a feedback when pressing the volume up/down buttons.
Is there any way to reinstall the whole OS? Or maybe authorize the Fingerprint of my PC to check if there's any display output via scrcpy?
Click to expand...
Click to collapse
It could one of many possible damaged contact surfaces or shorted/open surface mount devices including cpu or ram flat packs or mobo traces. Even after the water is gone if it wasn't promptly removed* damage will continue to surface long after the incident.
You need to tear it apart asap. Even a few minutes may be too long.
Water damage electronics are insidious failures waiting to happen.
Cut your loses.
*prompt removal is no guarentee but greatly improves chances of success.

I really need help, screen won't work at all

Emergency here, my phone fell in the water and now the screen is always black, and the touchscreen wont work. I have some really important stuff here, at first i was wonder if i could use scrcpy to use the screen, but i forgot my phone doesnt have dev options enabled and usb debugging disabled too. maybe i could try to just navigate the phone until i turn on usb debugging using a keyboard connected to the phone, but its basically like using a pc with the monitor off. any help?
Take it to authorized repair center and let them fix it.
Power off immediately.
I would strongly advise taking the rear cover off, even if you break it and disconnecting the battery asap!!! Time is of the essence, the faster the better.
Don't even think of trying to use it.
After you have disconnected the battery, flood it with anhydrous 99% isopropyl alcohol* (buy at drug store). It will absorb and displace the water.
Make sure it gets into all areas of device, allow to drain, use some inertia to help displace the mix by holding the phone and "flinging" it while not letting go. Low pressure compressed dry air or N2 works better. Repeat at least twice.
Dry as quickly as possible in a dry (RH>40%) room. Low pressure compressed dry air is better. Use a fan if nothing else is available.
DO NOT reconnect the battery until it's 100% dry!!!
If successful you will have saved your device.
Note: anhydrous Isopropyl alcohol is very hygroscopic so it will draw moisture from the air, the drier the air the better. Raise room temperature to 80°F or higher to drive the moisture out.
If it was contaminated with salt water, it's already dead... don't even bother.
*DO NOT use on any device with a LCD display as it will poison the display!!!
OK to use with any other type ie LED, OLED, AMOLED,etc

How to check dissembled Pixel 4a Mainboard?

Hi all,
I ditched my phone in water.
I disassembled the whole phone, cleaned everythign with IPA and dried it afterwards. Now I would like to check if the mainboard is still working.
I connected the battery, display and usb port to the mainboard and plugged a charger in -> no response (display black, no vibration, sound etc)
I assume that the batterie is completly dead as it discharged until it turned off.
Is this aready a clear sign for a broken mainboard or does it only boot when fully assembled? Just want to avoid to put more effort into the phone, e.g. replacing the battery etc if its already lost...
Thanks in advance!
Dry for at least 72 hours in a warm dry room with a fan on the mobo. The BGA chipsets can dry slow.
Isopropyl is hygroscopic so it's important to remember it may attract some moisture from the air while drying. Use only >92% or greater, 96% is best. Submerged the board in it for a couple minutes while moving it around.
Battery needs to be charged and good for the phone to boot.
Out of circuit the mobo especially is sensitive to ESD damage. Use your best judgment but more assembled is better than less assembled unless very familiar with the device.
Thanks for the reply! Phone is "drying" for two month now as I was already considering as "lost" after disassembling and no luck with first checks. But before getting the new 6a, I want to give it a last try Was just 7 month old when I dropped it :/
When I plugged the charger in, there was no sign of charging. So not sure if the batterie is broken or if its coming from the board, or both.
A new battery is quite expensive just for a test / to find out more is damaged.
Helikoptermann said:
Thanks for the reply! Phone is "drying" for two month now as I was already considering as "lost" after disassembling and no luck with first checks. But before getting the new 6a, I want to give it a last try Was just 7 month old when I dropped it :/
When I plugged the charger in, there was no sign of charging. So not sure if the batterie is broken or if its coming from the board, or both.
A new battery is quite expensive just for a test / to find out more is damaged.
Click to expand...
Click to collapse
If the battery sat near its auto shutdown voltage for 7 months it's DOA.
A charger likely won't supply enough current to boot.
The fact that it does nothing when connected to the charger is a bad sign.
Check for loose connectors, bent connector pins, etc.
Examine the mobo (power section especially) and connector pins closely for corrosion damaged caused by electrolysis.
Since you can't see the BGA pads if there's corrosion there...
Water exposure; power off immediately and pull the battery asap to limit damage. Salt or brine water is a death sentence though.
Anhydrous isopropyl alcohol is an excellent drying agent but it and any solvents can't be used around LCD's; it will irreversibly poison them.
LCD's are vented to atmosphere on the sides...
blackhawk said:
Water exposure; power off immediately and pull the battery asap to limit damage. Salt or brine water is a death sentence though.
Click to expand...
Click to collapse
Thats true, happened at work so I could do anything for the whole day and in the evening it was already dead. With some random screen on and offs during the day and "booting into fast mode" or something similar during the day.
Phone was not reacting to switch it off normally, screen was black and buttons did not react either
blackhawk said:
Anhydrous isopropyl alcohol is an excellent drying agent but it and any solvents can't be used around LCD's; it will irreversibly poison them.
LCD's are vented to atmosphere on the sides...
Click to expand...
Click to collapse
A thats interesting, I was already thinking that some water went inside the screen. Because I have quite some dark areas on the screen, which increased in size the first days. Looked like water got pulled in. Was hoping that when the phone gets warm again it will disappear...
blackhawk said:
The fact that it does nothing when connected to the charger is a bad sign.
Click to expand...
Click to collapse
Yeah, have the same feeling. Very unlucky as it was just rain water in a not perfectly closed rain jacket...
Will check the connectors and cables again but was already quite sure that they are all clean
Helikoptermann said:
Thats true, happened at work so I could do anything for the whole day and in the evening it was already dead. With some random screen on and offs during the day and "booting into fast mode" or something similar during the day.
Phone was not reacting to switch it off normally, screen was black and buttons did not react either
A thats interesting, I was already thinking that some water went inside the screen. Because I have quite some dark areas on the screen, which increased in size the first days. Looked like water got pulled in. Was hoping that when the phone gets warm again it will disappear...
Click to expand...
Click to collapse
That sucks. Prompt battery disconnect* can save electronics (flooded cars sometimes too).
LCDs are sort of witchy. The spot may or may not disappear over time. Have an old S4 that got sunbaked while charging. The display had multiple issues, barely usable. Thought it had fried drivers. Strangely the longer it sat unused the better it got. 3 years latter it almost 100%.
*Lol, 3 years ago I dropped my Buds case in a full cup of coffee, cream and sugar of course. It promptly sank to the bottom like a lead weight.
The Li is spot welded in. Immediately tore it apart, flushed with RO water, then with anhydrous isopropyl, allowed to dry for a day.
It's still working normally today. A drank that cup of coffee afterwards too

Water Intrusion Recovery

Howdy. I've got a TMo S10e that suffered water intrusion through the SIM slot (failed seal). The phone initially reported that the sd card was removed unsafely, and then mobile data went. I hadn't realized it was water intrusion at that time, as the phone's been really solid all these years. I attempted to reboot to resolve the issues and the phone entered safe mode. Following the on screen instructions I restarted to get out of safe mode. That's when the boot looping started. The phone will start, full screen is visible, safe mode label is visible in the lower left of the screen. After approx 5 seconds the phone will reboot and enter safe mode again, only to repeat the process until the battery is drained. When the battery was initially drained I removed the SIM tray and found the intrusion. Into a bag of rice it went.
After 24 hours in a bag of rice visible condensation (camera lenses, etc) is gone. I attempted to give it a minimal charge to start the phone and on powering up the same boot loop is present. In the 5 seconds before the forced reboot I'm able to swipe up to unlock and enter one digit. I'm guessing that this is moisture in a button or a button contact has been eroded. I'm crossing my fingers that it's not memory corruption. Google backup and SMS Backup had both been failing for months silently, and there is some misc data I'd like to recover that wasn't saved to the removable sd card.
Holding volume down and power should have booted me into recovery I though, but I'm presented with a screen that endlessly prints "SD Card selected by key input" to the screen.
I've done a lot of custom OS installs in years past and while it's been a minute, I've dabbled with adb. I'm hoping that it'll eventually dry out and allow me access, but I'm not holding my breath. Are there any methods that are available to extract data from this phone in this condition?
Rice doesn't work!
Power it down and leave it off.
Remove rear cover and disconnect the battery asap. Powered buses accelerate corrosion, a lot.
Put in adry warm to hot room on it's side with a strong fan on it for at least 48 hours. More is better.
Anhydrous isopropyl alcohol can be used, carefully, to absorb water. Don't get it in the cams or between the display/glass. Drain it away immediately then dry as above.
Rice did manage to get a fair chunk of the water, but it definitely didn't get it all. All the shops were closed until Monday late morning so it was worth a shot.
Took it to a local shop with a good reputation. They identified the buttons as the issue with safe mode, opened it up and dried out what remained of the water inside and left it open overnight. New buttons were installed the next day and it exited safe mode, connected to wifi and I was able to initiate a backup for the data I couldn't get at via ADB.
blackhawk said:
Rice doesn't work!
Power it down and leave it off.
Remove rear cover and disconnect the battery asap. Powered buses accelerate corrosion, a lot.
Put in adry warm to hot room on it's side with a strong fan on it for at least 48 hours. More is better.
Anhydrous isopropyl alcohol can be used, carefully, to absorb water. Don't get it in the cams or between the display/glass. Drain it away immediately then dry as above.
Click to expand...
Click to collapse
Desiccants actually work pretty well, that's the whole idea with the "bag of rice" thing. However, rice can be pretty dusty, which is why I always recommend silica beads instead. Silica rescue packs are available on Amazon.
V0latyle said:
Desiccants actually work pretty well, that's the whole idea with the "bag of rice" thing. However, rice can be pretty dusty, which is why I always recommend silica beads instead. Silica rescue packs are available on Amazon.
Click to expand...
Click to collapse
The phone needs to be opened up and the battery disconnected asap.
Passive air circulation is ineffective. Forced warm/hot air is needed. Heat effectively displaces water. The longer it takes to dry, the more corrosion damage. BGA chipsets and the power controller circuit are particularly susceptible. BGA contacts are inaccessible. Ribbon cables may need to be removed; their contacts can also be damaged especially if under power.
I provided the best shot to resolving this problem. Water damage is insidious and the device may fail eventually even if promptly dried. Time is of the essence; sooner is better. Best to pull the battery within minutes of water exposure and start the drying process. AMOLED's will be destroyed if exposed to water vapor.
Anhydrous isopropyl alcohol carries risks like leaving a residue on the display glass but removes water instantly. Never use methanol alcohol.
Never use isopropyl alcohol or any solvents around LCD displays, it will poison and destroy them.

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