Develop Bugs

[Q] Backlight starting to die?

Don't know if anyone else is experiencing this with their Play but as of a week or two ago the backlight started acting strange. The backlight will randomly stay off when I push the power button with the slider gamepad closed. Only way to make it come on is to pop out the slider. It seems to be random, and if I push on the slider edge slightly with my thumb with the slider closed the backlight randomly flickers, ranging from slight to severe.
The display is still working despite the backlight issues, I can open apps, and use the phone normally but the backlight flickers on and off. Makes it especially hard to use the phone in the dark.
Phone has never been dropped once.
I've replicated this problem with a variety of roms, both custom and stock. It's definitely not app related or even custom kernel related. It happens on a fresh wipe with stock rom with stock kernel. It happens on CM7 with custom kernel.
I'm curious if anybody else is experiencing this. It would tell me if it's just an isolated incident or if others are having this problem.

Sounds like a faulty connection to the backlight to me.

I had the same problem 2 days ago. Then I couldn't get my phone screen on at all!
I sent my phone back to Sony, even thought I bought it second hand. Phoned them up and talked to them. They asked what time of year I bought it so I said around August and then they gave me the address to send it to. Now I'm just waiting to see what happens next.
If your going to send your phone to Sony for repair then make sure you put the fresh firmware back on and un-root your phone as that breaks the warranty (unless they don't know about it)
Hope I helped you. If I did then click the thanks button

Sounds like a faulty ribbon cable to me. (cable that connects the screen to the rest of the phone)
You wouldn't need to drop it for that to go bad, It could just be a case of opening and closing the gamepad or lot.

Yeah good thoughts, most likely the ribbon. That really sucks because I've only had the phone for 7 months, and I've taken excellent care of it. Sounds like a major design oversight.
Mine is probably near complete failure at this point. It's taking a lot more effort to keep the screen on now. Fearing soon it won't work at all.

In hopes that this might help someone else down the line, I was able to fix my problem. Yesterday the screen pretty much quit and I had no choice but to try and solve it myself or buy a new phone.
Using this disassembly video as a visual aid I carefully pulled my phone apart: http://www.youtube.com/watch?v=-3n5ZfkqhzE
You'll need a torx T5 tool to pull out all the screws but they are cheap.
Underneath the phone and jammed into the screen ribbon was a rather thick hair just hanging out. Somehow it buried itself in there. I removed it, unplugged and replugged the screen ribbon and cleaned the dusty inside with a q-tip and reassembled it all together.
It works fine now, so hopefully this helps someone else avoid having to pony up for a new phone. For those under warranty probably best to send back but for those like me with no warranty it's worth the shot.

[Q] Weird touchscreen behaviour (only works when keyboard is flipped out?)

Hi everyone,
I've had my Desire Z for little over 2 years now and two months ago (was running CM7.2 at the time) I started getting a weird issue where my touchscreen would only be responsive when the keyboard was slid out (so the opposite problem of what quite a few other people have reported where the touchscreen becomes unresponsive when the keyboard is out). The status LED would also stay off whenever the keyboard was closed, and the keyboard backlight didn't come on anymore at all. Also, I had to make sure that the keyboard was slid out during boot, if the phone booted without the keyboard out the screen would not become responsive at all until after another reboot. My earpiece speaker stopped working around the same time so I was wondering whether it was just an issue with the flex cable becoming a bit loose, but the touchscreen would consistently start working again when I flipped the keyboard out, and also the physical scroll button on the top bit would always work, so I was still hoping it would be some weird software issue.
I then upgraded to Flinny's (amazing) Andromadus ROM (build 22, complete data+dalvik wipe) after which the keyboard backlight started working again, but the rest remained pretty much the same. Since then the touchscreen issues have been getting worse, so that I sometimes have to flip the keyboard in and out again a few times, or turn the screen on or off with the power button several times before it becomes responsive again, but then it tends to work fine until I lock the screen again, with no noticeable dead spots anywhere on the screen. I've had days where it worked all day without problems (except having to flip out the keyboard, that's been a constant for the past two months), and then today I haven't been able to get the screen to do anything at all even after dozens of reboots.
I've already bought a new digitizer and am all ready to put it in (I'll have to replace the broken earpiece anyway), but was wondering whether anyone has any thoughts on whether it could still be a software issue after all, or if anyone has experienced anything similar? The thing with having to flip the keyboard out to get not only the touchscreen but also the status LED to work is just so weird and makes me doubt that it's a pure broken digitizer or lose flex cable issue, so I'm wondering whether it would be better to first try reverting to a stock ROM before taking on the messy sticky glue stuff (I should be fine but still, never done it before)?
Many thanks!

From what you describe my best guess would be the main flex cable is what needs to be replaced. Flash a touch based recovery and see if you have the issue there as well, if so its very unlikely that its anything but a hardware fault
Sent from my Nexus 4 using Tapatalk 2

Thanks for the heads-up, I've been playing around a bit more with software and I do manage to get the screen working again occasionally, typically after the second boot into a newly flashed ROM or restoring a backup, and only until one or two reboots later when it becomes completely unresponsive again. I've tried CM 7.2.0 as well as Flinny's Andromadus 10, and it is only complete flashing that does the trick, cache wipe or factory reset alone does nothing. The two occasions where the touchscreen worked were still limited to when the keyboard was flipped out, and it also had to be flipped out during boot, otherwise nothing would work. I've learned to navigate my way around the phone by just using the hardware navigation button, but I'll have a close look at the flex cable when I take it apart to replace the earpiece speaker tonight...

Hello,
so I took my dear phone apart yesterday to replace the broken earpiece - everything went fine but after reassembly the replacement earpiece isn't working either, which leads me to think that all those little broken bits might actually be related to some contacts being a bit lose, all in the same region. Should've thought about that earlier really since the earpiece and the LED (only works when keyboard flipped out) are both in that top region that the digitiser data presumable also has to run through before passing through the flex cable.
In any case, I also took a picture of the flex cable which is slightly bent but doesn't seem straightforwardly damaged (see attachment, that thing on the right is *not* a rip). Think it's worth trying to replace it anyway?
What was truly bizarre is that after the first boot following reassembly the touchscreen worked quite consistently for the entire evening - I thought I might've fixed a lose contact by un- and replugging the digitiser cable, but then the screen went nonreactive again at some point. I wonder if the working screen was again actually related to some software reset caused by the battery being taken out for so long? In the meantime the actual screen and trackball are still working away perfectly. Bizarre.

Just to let people know the solution to the mystery: the increasingly odd behaviour was actually caused by an initially small rip in the flex ribbon cable that got bigger and bigger - it's actually half-visible in the picture I uploaded above, only that the rip is where the cable comes out from underneath the case, and not where it's wrinkled!
Just in case it could be useful for anyone, here's the (top half of phone) components in the order in which they failed on me, which I guess corresponds to the order of the respective data lines in the ribbon cable (from the top of the phone towards the center):
environment brightness sensor (I thought that the sensor had been broken for almost a year, but as soon as I rebooted with the new flex cable I noticed how my phone stopped shining into my face at full brightness - if your brightness sensor gets stuck reporting the same (low) value this means your flex cable is on its way out!)
earpiece speaker
status led
touchscreen
screen (non-alignment with edge of screen, visual artefacts)
screen (fade to black/power interrupt)

obstacle3 said:
Just to let people know the solution to the mystery: the increasingly odd behaviour was actually caused by an initially small rip in the flex ribbon cable that got bigger and bigger - it's actually half-visible in the picture I uploaded above, only that the rip is where the cable comes out from underneath the case, and not where it's wrinkled!
Just in case it could be useful for anyone, here's the (top half of phone) components in the order in which they failed on me, which I guess corresponds to the order of the respective data lines in the ribbon cable (from the top of the phone towards the center):
environment brightness sensor (I thought that the sensor had been broken for almost a year, but as soon as I rebooted with the new flex cable I noticed how my phone stopped shining into my face at full brightness - if your brightness sensor gets stuck reporting the same (low) value this means your flex cable is on its way out!)
earpiece speaker
status led
touchscreen
screen (non-alignment with edge of screen, visual artefacts)
screen (fade to black/power interrupt)
Click to expand...
Click to collapse
I'll for sure keep that in mind. Mine is still going strong for the time being, but it's good to know some warning signs if I need to replace parts or if it's time to get a new phone

fireball0093 said:
I'll for sure keep that in mind. Mine is still going strong for the time being, but it's good to know some warning signs if I need to replace parts or if it's time to get a new phone
Click to expand...
Click to collapse
Replacement parts all the way, the repair was 15$ and it feels as good as new! Well, it could do with a new battery but that's just another 5..
Just realised that the proximity sensor should actually be added to the very top of the list - just noticed that faint red light when taking a phone call, don't remember seeing that in almost a year :]

obstacle3 said:
Replacement parts all the way, the repair was 15$ and it feels as good as new! Well, it could do with a new battery but that's just another 5..
Just realised that the proximity sensor should actually be added to the very top of the list - just noticed that faint red light when taking a phone call, don't remember seeing that in almost a year :]
Click to expand...
Click to collapse
That's not a bad cost at all. I know I'm going to have to replace my keyboard in probably 2 months or so (maybe sooner) because some buttons are starting to not work. Other than that fact my phone is currently still going strong for being going on a 3 and a half year old phone

WiFi is gone

I've had this tablet (SM-P600) for almost a year now & it has worked perfectly. Over the last week or so, the WiFi has been randomly turning on & off. Not just losing signal, but actually showing as off in the menus. As of this morning, wifi will not turn on at all. Just says "turning on" on the screen & sits. Never gets to the next screen showing all the open networks.
Everything is fully backed up so I went into recovery tonight. Did the full factory reset and wipe procedures. Tablet boots back like it is as supposed to, but wifi wont turn on when getting to that screen in the initial setup.
Tablet has been well cared in a case, not dropped, and not gotten wet. However I am still positive this is a hardware issue.
Any ideas for things I might try? Help!! Thx in advance

I've the same problem with my galaxy note 10.1 2014 edition SM-P605 :crying: Still haven't found solution

I am almost 100% certain this is some type of hardware problem. I tried flashing about 3 different ROM's and 3 different kernels, all of which successfully booted up. I finished by doing a 100% re-wipe (data & system included) & reinstalling a pure stock kernel and firmware. On every single revision, the words "turning on" would appear when clicking the WiFi option, but then it would get stuck. Message would eventually clear & I could continue using everything on the tablet . . . . . . . just no WiFi or Bluetooth functionality.
Final attempt was to gently remove the back cover. When lightly tapping around different points on the MoBo, the names of my local wireless networks would OCCASIONALLY appear. At one point they locked in & I really thought I had it. However, the whole thing disconnected again after a few minutes & I was back to square 1. :crying:
I never could figure out the perfect sweet spot to pinpoint the problem. My guess now is either a chip or ribbon cable that isn't seated properly, but I poked and pushed (gently!) on everything that was visible without removing any hardware other than just the back cover. Does anyone have a link to the layout of the motherboard that shows EXACTLY which piece is the WiFi/BT module? I did find an online disassembly tutorial with a random Google search, but for some reason they failed to identify this particular module.
Sorry for the long post, but I feel I am SO CLOSE to figuring this out once and for all. Just need a little more tech help to push across the goal line. Thanks!!
~Vol

Vol4Ever said:
I've had this tablet for almost a year now & it has worked perfectly. Over the last week or so, the WiFi has been randomly turning on & off. Not just losing signal, but actually showing as off in the menus. As of this morning, wifi will not turn on at all. Just says "turning on" on the screen & sits. Never gets to the next screen showing all the open networks.
Everything is fully backed up so I went into recovery tonight. Did the full factory reset and wipe procedures. Tablet boots back like it is as supposed to, but wifi wont turn on when getting to that screen in the initial setup.
Tablet has been well cared in a case, not dropped, and not gotten wet. However I am still positive this is a hardware issue.
Any ideas for things I might try? Help!! Thx in advance
Click to expand...
Click to collapse
What model is your tablet?
This was sent from my Lenovo A850 via XDA mobile app.

irfanadli97 said:
What model is your tablet?
Click to expand...
Click to collapse
Sorry about that. It's just the initial release plain jane WiFi model. SM-P600

Update:
After a little more poking and prodding on the MoBo, I'm starting to see activity. Tablet will finally connect again, but will only hold the connection for 10-15 seconds and then drop back out. A few seconds later the cycle repeats.
I really wish I could find a good hi-res photo of the motherboard to help. HAS to be a simple loose connection, or maybe a not-so-good solder point somewhere???

Vol4Ever said:
Sorry about that. It's just the initial release plain jane WiFi model. SM-P600
Click to expand...
Click to collapse
......
never heard of 'em, is it a cheapo tablet? In my country there's a store of them (Allwinner 6.6" tablet with microSD slot, 2gb internal w/o bluetooth WIFI ONLY INTENDED FOR CASUAL GAMING, or should I call it kids only tablet, RM130 ($35))
That thing has a cheap plasticy housing, unneat design but has a pretty good performance (it plays dead trigger pretty well)
This was sent from my Lenovo A850 via XDA mobile app.

irfanadli97 said:
......
never heard of 'em, is it a cheapo tablet?
Click to expand...
Click to collapse
SM-P600 is Samsung's actual model number for the WiFi only version of the 2014 Galaxy Note 10.1. Most definitely NOT a cheapo tablet!! Although this wifi issue makes me wonder. I had the functionality back for about a day or so, and then it disappeared again. This has to be a simple case of a loose connector, but I sure can't find it. Ugh. Utterly frustrating.

oo...my bad
maybe software issue
This was sent from my Lenovo A850 via XDA mobile app.

What firmware version are you using because I am having the same issue. I manually updated to the september update (P600UEUCNI1) for the wifi version and started experiencing the same issue.

Same here. I think it's an issue with NII firmware.

*****PARTIAL solution*****
I have proven 100% that mine is problematic hardware . . . . . NOT software or kernel. For the time being my WiFi is back up & seemingly stable. I had to remove the back from the tablet for the fix. You have to be *extremely* careful, but it just snaps off with no screws. Lots of YouTube videos if you choose to attempt, but please don't say I didn't give you fair warning!
The reason I say partial solution is that I haven't pinpointed the exact location of the short. I am 99% sure it is somewhere on the extreme upper left hand corner as you face the front of the tablet. There are a couple of ribbon connectors in that area, and a few snap on type connectors that look like little motherboard chips. After gently poking & prodding the ribbons and disconnecting & reconnecting the snap connectors (being CAREFUL; I cannot stress this enough), my WiFi reappeared.
My final tip is to keep the screen on the page that shows the list of available networks. If you are having the same problem I was, this screen will just show "turning on" and nothing else for the WiFi. While poking around, I would occasionally see the list of networks pop up & then go back off. I finally hit whatever the magic spot is, and the networks held. Snapped the back cover on again, and I've been online for probably 4-5 days now without a single hiccup.
And before I get flamed, I know how dangerous it is to poke around with a powered, exposed tablet. There are probably certain points that could make connection and FRY the entire thing in an instant. I was just willing to take the risk as my tablet was useless without network capability. I had nothing to lose. I would recommend at least trying to poke & prod with the tablet OFF a few times to be safe, but I personally got tired of rebooting over & over & over & over. My luck sucks. With the tablet ON, I was at least able to monitor when something was happening.
Good luck if you attempt it!!
~Vol

Vol4Ever said:
I've had this tablet (SM-P600) for almost a year now & it has worked perfectly. Over the last week or so, the WiFi has been randomly turning on & off. Not just losing signal, but actually showing as off in the menus. As of this morning, wifi will not turn on at all. Just says "turning on" on the screen & sits. Never gets to the next screen showing all the open networks.
Everything is fully backed up so I went into recovery tonight. Did the full factory reset and wipe procedures. Tablet boots back like it is as supposed to, but wifi wont turn on when getting to that screen in the initial setup.
Tablet has been well cared in a case, not dropped, and not gotten wet. However I am still positive this is a hardware issue.
Any ideas for things I might try? Help!! Thx in advance
Click to expand...
Click to collapse
I bought my Note in March of this year, I started having the WiFi issue after the April firmware update. At first I would get the Connected to... message at random times, even though I had full signal strength. At the end of September, I started losing connection at random times and in the middle of October, I had to send it in to Best Buy's Geek Squad service to have them repair it. It is a hardware issue, as the no matter what firmware version I use, it will never connect to the router. I know it, Geek Squad is aware of it, as I have sent it in for repair twice so far. I would have to send it in a third time before they will think about replacing it with a new Note. I will admit, that before I updated it in May, I did root it, because I tried to remove the Business Week+ and New York Times apps, as I never used either one of them. I tried disabling them, only to have them reactivate and update themselves.

Damn, what I read here is not good news. My SM-P605's died yesterday.
With Tapatalk on my Galaxy Note 10.1 (2014)

Hardware issue for sure. Same problem with mine. Opened the back case, disconnected the upper right (as your looking at the screen) small ribbon, reconnected, and boom, perfect wifi once again!

The EZ Package Disabler app is fine for debloating rooted and non-rooted devices with Touchwiz roms. It uses Knox, so that mustn't be removed. The apps are still on the system partition, but are completely dead now. While other apps, especually for non-rooted devices kill the system apps during boit and try to prevent their restart. But during boot the whole stuff is active until the app kicks in, allowing the system apps to receive updates, communicate, spam free flash mem etc.
The app wirks the same way on my rooted P605 and unrooted S5. And gives a reason to buy Samsung stuff, unlike Touchwiz and its bloatware. As far as custom roms go, i found that of my old LG L9 much better. Even if the early roms were AOSP 4.0.4 based, then 4.1.3, they had already had the fresh & bright look & feel of the future Kitkat, and a few useful enhancements like an integrated backup tool, which was more simple, but for me as useful as TB.
As for the main problem here, i think using a case with a hardened backside, and not one if these with a big hole(though being better than nothing), prevents oroblens like battery, display and seemingly wifi connectors loosening. Or bad solder joints. The backplate of the note gives thru any pressure on the back, especially in the middle area. It then rests on the battery, metal shields, connectors and stuff. This seems to generate enough wear over time for problems. The same back plate on a much smaller device(my S5, but that has a subchassis covering the innards, too) would be much stiffer, and my 7" tablet has an aluminium unibody case, such trouble is unknown there.

Hi Gents..
same problem here... I used to own a SM-600 purchased in 2014 unfortunately I lost it... (the first tablet worked without any proble until I lost it...) than I managed to found the same modell brand new on amazon... it worked for 2 weeks and 2 days ago wifi died... but funny enough not straight away.... first couple time just switched off the wifi... I managed to switch simply back... next day it only worked if restarted the device... now factory reset nothing... If it is hardware related why worked 2 weeks witout any problem? If it is software related why not working after software reset? Only installed a few apps from the store.. the device did not overheated or physically damaged...

I have the exact same problem.
Since I bought this a long time ago, I have to pay for the repair. I just want to know if it is worth it. How much did it cost you (if you bothered)?

In my opinion it would be foolish to spend a dime to repair a 4 year old tablet. If the battery is original, it may well be near the end of its useful life as well. FWIW, I bought this tablet used about 8 months ago and have not experienced this wifi problem.

It's still so well equipped, that you can't simply replace with a modern entry level or midline tablet, but with a top of the line one, so a repair is well an option.
I just don't have a clue about the SoCs performance level. To which current ones it would equal and where things get better. I can only compare it to my similarly(Snapdragon 801) equipped phone and my cheap 7" tablet's quad core Mediatek SoC, and that is considerably worse, though being three years newer.

N7 screen went black

Yes, like it turned itself off but it did not go off as I was still getting audible email notifications. Tried everything speaking with Google support and then even Asus support who told me to go to their website and fill in an RMA form. This unit is 13 months old-out of warranty. There is nothing on the form relevant to the nexus to fill in so you cannot continue with it. So I am stuck right now and do not know what to do if anything. Any help would be appreciated.

claypoole said:
Yes, like it turned itself off but it did not go off as I was still getting audible email notifications. Tried everything speaking with Google support and then even Asus support who told me to go to their website and fill in an RMA form. This unit is 13 months old-out of warranty. There is nothing on the form relevant to the nexus to fill in so you cannot continue with it. So I am stuck right now and do not know what to do if anything. Any help would be appreciated.
Click to expand...
Click to collapse
Normally, 3 things can go wrong:
1. The cable is not connected properly. This could be caused by any impact. You take off the back cover and reseat it. It's the amber cable that runs the length of the battery. Be sure to check both ends. The one on the motherboard's end is in plain sight. The other end is hidden beneath the daughter board at the bottom of the tab, so you need to remove it to inspect the connection.
2. The backlight which illuminates the display went out. You can check this by turning the tab on and taking the tab to a dark room and shine a flashlight on the screen. If you can see the icons or the boot page, the back light is bad. The bad news is that you'd have to remove the lcd/touchscreen unit to replace the backlight. 10 times out of 10, when you do this on an original tab, you will break the touchscreen. Since it's glued to the lcd with LOCA (liquid optically clear adhesive), you will have to separate them, fix the backlight, buy a new touchscreen, then reassemble the whole thing. Most people would find it simpler to just buy a new lcd/touchscreen combo. If you're game though, I can give you an lcd back with a working backlight strip.
3. The video circuit on the motherboard went belly up. To test this, you need a micro usb to HDMI adapter like the one here , and a newer lcd TV. If nothing shows on your TV, the GPU is probably dead, in which case the only practical solution is to replace the motherboard since it's impossible to replace the GPU at home.
Good luck.

graphdarnell said:
Normally, 3 things can go wrong:
1. The cable is not connected properly. This could be caused by any impact. You take off the back cover and reseat it. It's the amber cable that runs the length of the battery. Be sure to check both ends. The one on the motherboard's end is in plain sight. The other end is hidden beneath the daughter board at the bottom of the tab, so you need to remove it to inspect the connection.
2. The backlight which illuminates the display went out. You can check this by turning the tab on and taking the tab to a dark room and shine a flashlight on the screen. If you can see the icons or the boot page, the back light is bad. The bad news is that you'd have to remove the lcd/touchscreen unit to replace the backlight. 10 times out of 10, when you do this on an original tab, you will break the touchscreen. Since it's glued to the lcd with LOCA (liquid optically clear adhesive), you will have to separate them, fix the backlight, buy a new touchscreen, then reassemble the whole thing. Most people would find it simpler to just buy a new lcd/touchscreen combo. If you're game though, I can give you an lcd back with a working backlight strip.
3. The video circuit on the motherboard went belly up. To test this, you need a micro usb to HDMI adapter like the one here , and a newer lcd TV. If nothing shows on your TV, the GPU is probably dead, in which case the only practical solution is to replace the motherboard since it's impossible to replace the GPU at home.
Good luck.
Click to expand...
Click to collapse
Did anyone else read this response and want to hit the edit button, and then type in huge letters "Time to buy a new Nexus!"

Thank you for your detailed reply. I checked the cable from the MB at both ends. Seems OK on the connections. I am unable to turn on the tab to check the backlight. That's about as far as I can go with it at this point. I am thinking that this tab is toast and to make matters worse, the abominably bad Asus customer service. I am considering replacing this with a Samsung and be done with it.

claypoole said:
Thank you for your detailed reply. I checked the cable from the MB at both ends. Seems OK on the connections. I am unable to turn on the tab to check the backlight. That's about as far as I can go with it at this point. I am thinking that this tab is toast and to make matters worse, the abominably bad Asus customer service. I am considering replacing this with a Samsung and be done with it.
Click to expand...
Click to collapse
Hey, don't lose hope! Samsung is not any better specs or quality-wise (especially the display). If you're gonna butcher the thing anyway, might as well find out. I was gonna suggest to lend you a used lcd for you to test, but I realize people for some reason are extremely wary of gratuitous offers so I won't. But if you value it, try to get a screen with a good lcd but broken digitizer on Ebay. They wouldn't cost more than 15 bucks. Once you can determine it's not the motherboard, we can go from there. I can guide you on the replacement part if you want. I'm just a hobbyist, but I have messed around with this thing enough to tell.

Graph, you are kind to offer. I also have noticed that the glass has a few cracks in it as well. At this point, I can't turn it on. It seems like when I punch the on button in there is extremely little movement if at all. So I don't know if it is still on which I don't this it is or it shut itself off. When it was black screen and on, I was getting my email notifications audibly but since yesterday-none. I am not looking to spend big bucks on these things as essentially all I do mostly is use for reading. I do want to stick with android if I replace this. I know samsung does not have as good resolution but seems to get good reviews from users.

Slowly increasing hardware problem

Hi all,
I have a general hardware problem with my Samsung Galaxy Tab S4. Maybe someone here has an idea or tip for me.
I still used the factory software without any rooting or unlocking the bootloader. So everything original and up to date.
A few month ago the tablet began to restart in the middle of using it. At the beginning it happened seldom, but then more and more often. Also during the restart new restarts happened more and more often, so that it took several retries, until it started again. Now it is not usable anymore, because it is not running longer than a few seconds before the next restart if it happens to boot completely at all.
I was able to make a factory reset but this didn’t solve the problem.
My first theory is, that this could be a problem with the battery, that it is slowly dying and had more and more problems to hold the voltage. But the problem also exists when the power supply is connected. So I am not sure if this rules out the possibility, that this could be cause by the battery? Does somebody know how this is internally wired, if a broken battery could still have a negative effect when the power supply is connected?
Do you have other ideas/advices, what could be the problem or would could be helpful to do?
Thanks in advance for any help.
Best

The USB power input can't sink enough current to boot it or even run it without the battery acting as a reserve during peak usage spikes.
Replace the battery and go from there.

Thanks, then I will try this.

Vertex9999 said:
Thanks, then I will try this.
Click to expand...
Click to collapse
Hi Vertex, have you tried this already? I have pretty much the same problem and the battery was also my first intuition, but I don't know if buying a new one is worth it. Thanks!

Hi,
unfortunately I didn't had time to do it yet. I want to change the battery myself and for that I will need time and somebody to borrow me a hot air gun, because everything is glued together.
I will report, when I have done it but it will be at least a few weeks.

Alright, so I'll probably try it sooner, I'll update after replacing the battery. Also, if you haven't tried it yet, you might want to try just disconnecting the battery from the motherboard and connecting again after like 20s, I've read that it sometimes resolves this problem, but it didn't work for me. Fortunately removing the back lid of tab s4 is pretty easy, I used hairdryer, so with heatgun it should be even easier.

Thanks for the tips. I am currently on vacation but when I am back I will also try with a hairdryer.
Any additional tips for removing the back lid to somebody doing it the first time beyond what you can see in the youtube videos? How do you glue it back together?

Hi, sorry for the late reply.
I have eventually replaced the battery, and nothing changed unfortunately… I did a factory reset, etc. However I also had an issue that you didn't describe in your original post, which is that USB connection is not working, it only charges the battery, when connected to the PC while booted it's just not visible at all (tried with several cables, two computers, on windows and linux), when in download mode it kind of shows up, but it's not recognized and no drivers or any solution that I've found are working, so I don't know if it's still hardware problem something with the USB related parts or something in the system on lower level. Well, I'll be trying.
About the back lid. Beyond YT videos only thing that comes to my mind is patience. About the glue, you have few options and it depends a bit on how removing the cover goes. 1) glue stays in the more or less same condition as before removing the cover - that's how it went for me - in that case you can just reuse it, just by closing the cover and pressing it down for some time, it's probably not as strong as new but for me it worked just fine, especially if you use a book cover for the tablet there won't be a problem.
But if the glue came off, wrinkled a lot, or just doesn't stick anymore, 2) you can either use a special epoxide glue often with signature like T-7000 or T-800 but if you just look for a glue for smarphones you'll easily find it. Or 3) Buy a special sticker for this exact device which has a specific shape, it's pretty much the same thing as is used by manufacturer.