Develop Bugs

Black Screen, Blinking Red and Blue LED after boot

Hi all,
Before someone says it, yes I did look around for other threads before posting one of my own. I was not able to find the problem that I am having, nor a working solution.
I am currently running CM12.1 on a Sprint G3 (LS990). This morning, I woke up and found that my phone had frozen while charging overnight. No problem, this has happened before, so I unplugged it and pulled the battery out and rebooted. It was working fine, and then I noticed an update for CM. I hit download, and went to go brush my teeth. When I came back, I saw that it had frozen mid-download. Now it wasn't installing anything; the CM built in updater was just downloading the latest nightly. I waited 5 minutes for it to become responsive, but it never happened so I pulled the battery once again.
Now when I held the power button to start my phone, I saw the LG splash screen as normal. After that, the screen went dark and the LED began blinking red and blue. No matter how many times I pulled the battery to reset my phone, this would occur. I attempted to enter Recovery mode, but in this case after the splash screen the LED would briefly light up blue, and then the phone would reboot, and the cycle would repeat. The same would occur when I tried to boot into download mode.
So now that I cannot boot into anything at all, I assume that my phone is bricked. It is still covered under the limited manufacturer warranty, and since I can't boot up at all I assume it doesn't matter that it is rooted, but before I contact LG I would like to see if anyone here has any ideas.

Before sending it back, have you tried to use the KDZ tool to restore it?
http://forum.xda-developers.com/showthread.php?t=2785089

RapHaeL_4_4_4_ said:
Before sending it back, have you tried to use the KDZ tool to restore it?
http://forum.xda-developers.com/showthread.php?t=2785089
Click to expand...
Click to collapse
That requires the phone to be in Download mode, and it won't enter Download mode, so I have not tried that.

Well, this happened to me after I flashed TWRP from Flashify on my LG G3 D855 in the day before yesterday and I just had to take the battery out and put it back in, and then I had to boot into download mode. Since you can't even boot into download mode, I'm almost sure the phone is bricked

FelipeGouliouras said:
Well, this happened to me after I flashed TWRP from Flashify on my LG G3 D855 in the day before yesterday and I just had to take the battery out and put it back in, and then I had to boot into download mode. Since you can't even boot into download mode, I'm almost sure the phone is bricked
Click to expand...
Click to collapse
Yeah I assumed as much. Sent it to LG today, so thank you guys for trying to help.

ashingtondc said:
Yeah I assumed as much. Sent it to LG today, so thank you guys for trying to help.
Click to expand...
Click to collapse
You HAVE to flash your phone if it was rooted or bump'd, otherwise, it won't be under warrenty, even if it don't boot, they're not stupid..
Every post have: "Your warranty is now void." in it for a reason.

LG G4 H811, crashed and bricked?

Hello to all of you who's reading, I ask for help from all of the skillful and knowledgeable folk in this wonderful community, I have a LG G4 phone that ran on CM.13, everything was running fine up until two days ago, phone just froze for a minute, nothing was responding, it crashed and LG logo came on, attempting to power on, but 10-15 seconds later it goes blank and lights up LG logo again... Now I've tried getting into TWRP but factory data reset msg comes up, after hitting yes and yes screen lingers frozen for another half a minute until LG logo shows up. I can get into download mode and tried flashing a stock image with LG Flash Tool 2014, it looked like it went through successfully but ends up doing the same thing... loops without ceasing. Do any of you have any idea what is going on and how can I get it fixed? Thanks for reading!!

LG G3 D855 Stuck in Weird Bootloop...

Hey! Check the bottom for TLDR.
I have had my G3 since they came out (have the 2GB, 16GB RAM version), and even got the G4, but remained with the G3 since it didn't have any issues with rooting and recoveries...
Anyways, I was talking to my brother on WhatsApp yesterday and ended up checking out my Hangouts messages at the same time. I believe I accidentally hit the camera feature on Hangouts, and then everything froze. I could still talk to my brother, but I could not get to the home screen or even change from looking at Hangouts. I turned off the screen in hopes that I could get back in, but when I turned the screen back on, I could not log into the phone (I do not have a pin or password, it has no lock at all).
After a few more minutes talking to my brother, it suddenly shut off. When I tried to turn it on it went into a bootloop where the front light changes different colors, and the LG logo continues to show that shine going around the logo.
I was able to get into download mode and went ahead and tried to flash a KDZ as per instructions (I have done this in the past). The install would complete and the phone would give the prompt about updating all the apps. Once that was done, it would show the LG logo and again for about ten minutes. Afterwards, it would get stuck in updating all the apps again and performing the same process...
I also tried using the LG PC Suite and trying to "Restore upgrade errors", but every time I would click that option, I would get a Windows error that something happened and close out the program (it never recognized the phone). I then used the LG Mobile Support Tool, which allowed me to perform an update for the firmware. It too completed, but then went back into the process of updating apps, showing the LG logo, then looping.
The final thing I tried was doing a Factory Reset. I was able to get to the area, and when selecting yes, it immediately went to the LG logo and "Life's Good" sign, which it would never get passed. This is also what happens when I try to turn on the phone and wait.
I contacted LG, which was pointless, as I expected. They wanted me to go to a local repair shop, which is of no use to me if they can only perform the same things I have done.
TLDR: My phone can get into download mode and the Factory Reset area, but flashing stock firmware, or performing the Factory Reset, still leads me into one of two bootloop situations. LG PC Suite and LG Mobile Support Tool seem to be of no use.
Does anyone have any suggestions? Is there anything I can try that I haven't?
Thanks in advance!

LucidPhusion said:
Hey! Check the bottom for TLDR.
I have had my G3 since they came out (have the 2GB, 16GB RAM version), and even got the G4, but remained with the G3 since it didn't have any issues with rooting and recoveries...
Anyways, I was talking to my brother on WhatsApp yesterday and ended up checking out my Hangouts messages at the same time. I believe I accidentally hit the camera feature on Hangouts, and then everything froze. I could still talk to my brother, but I could not get to the home screen or even change from looking at Hangouts. I turned off the screen in hopes that I could get back in, but when I turned the screen back on, I could not log into the phone (I do not have a pin or password, it has no lock at all).
After a few more minutes talking to my brother, it suddenly shut off. When I tried to turn it on it went into a bootloop where the front light changes different colors, and the LG logo continues to show that shine going around the logo.
I was able to get into download mode and went ahead and tried to flash a KDZ as per instructions (I have done this in the past). The install would complete and the phone would give the prompt about updating all the apps. Once that was done, it would show the LG logo and again for about ten minutes. Afterwards, it would get stuck in updating all the apps again and performing the same process...
I also tried using the LG PC Suite and trying to "Restore upgrade errors", but every time I would click that option, I would get a Windows error that something happened and close out the program (it never recognized the phone). I then used the LG Mobile Support Tool, which allowed me to perform an update for the firmware. It too completed, but then went back into the process of updating apps, showing the LG logo, then looping.
The final thing I tried was doing a Factory Reset. I was able to get to the area, and when selecting yes, it immediately went to the LG logo and "Life's Good" sign, which it would never get passed. This is also what happens when I try to turn on the phone and wait.
I contacted LG, which was pointless, as I expected. They wanted me to go to a local repair shop, which is of no use to me if they can only perform the same things I have done.
TLDR: My phone can get into download mode and the Factory Reset area, but flashing stock firmware, or performing the Factory Reset, still leads me into one of two bootloop situations. LG PC Suite and LG Mobile Support Tool seem to be of no use.
Does anyone have any suggestions? Is there anything I can try that I haven't?
Thanks in advance!
Click to expand...
Click to collapse
I had the same issue about two weeks ago...tried everything with no success.....
I send my device to LG reparation center...a week ago
Still waiting for an answer...
Probably battery powering issue or motherboard.....

Have u tried LG Up?

opened the phone removed the motherboard and gave a heat blow using a hair dryer on my blue screened LG G3. worked since then no reboots or blue screen. dont know for how long though. try that maibe might work for you

Need Help Bootloop on LG G7

Hello, I have the LG G7 thinq. The Device is on Bootloop but I don’t know why!! It starts again and again. It comes to the Red LG Logo and than It boots again. Please Help

zzman31 said:
Hello, I have the LG G7 thinq. The Device is on Bootloop but I don’t know why!! It starts again and again. It comes to the Red LG Logo and than It boots again. Please Help
Click to expand...
Click to collapse
Please describe what happened prior to this before you start a whole big riot again.

Hello, I have this problem well. It started 8 hours ago. I was using it normally, no root or anything. And suddenly when I take it out of the pocket, it just keeps restarting.
I'd like to recover all my data before hard reset. Any help please?
Couldn't even turn it off, I had to wait until battery died.

Hello, same problem here. 2 hours ago I received a WhatsApp message and suddenly it restarts again and again.

Me too! But after two factory restarts I found the problem I guess.
For me, it occured twice when I started Airplane mode and after that everything went to...
Now I am affraid to start airplane mode again
What ROM and version are you guys??
V10f-EUR-XX

My version is V10k-EUR-XX.
After 2 factory resets it looks like my SIM card is the problem.
Without card the phone starts... But in my old LG G6 the SIM card works well.

I tried it with and without SIM as well, but it behaved the same. Sometimes I got into the system, but it just got stuck right away and bootlooped again.
But weird, because for me its airplane mode, which disables/enables celular, so SIM again.
I got T-Mobile, you?

I got t-mobile, too.

So lets wait for stormeye25, I wonder if he also has t-mob

Airplane mode is working well. Without a SIM ...

I am working with SIM. Only when I switch airplane on it stucks again. First time it was me turning airplane off, second time turning it on. Always with SIM and working celular

I tried without sim. Same problem. Also sometimes it boots up, but freezes after 2 seconds. I have the Europe version

I have same problem and i dont know what to do. Problem start about 5 hours ago (what i know last working time was 2:00AM CET). Itself reboot in boot screen or immediately on screen lock after start. I did factory reset, it work for few minutes and again. Version G710EM DEC (germany open market) last FW

It's something from lg ?
Update gone wrong maybe

Exact same problem on my G7 Thinq. Started about 8 hours ago. Boot loop, managed to get it in factory reset mode. Did nothing. Managed to reset it again (without the SIM in) then it booted. After reset it does not recognize (any) SIM. Called Tmobile to ask some questions about repair-process, they told me I was the 3th today with this problem. At this point I wish I wrote down my Google's 2FA recover keys :'). Can't access anything at the moment.

Same bootloop here, g7 thinq bought in Hungary Unlocked, but it downloaded the local t-mobile branding.
It was untouched on charger. When I wanted to pick it up it was already bootlooping and hot.
Put it into freezer, it booted, wallpaper lockscreen arrived, but nothing more.. it was stuck and started bootlooping again after like 30 secs.
Any info / resolution you have?

Okay so it happened again for me with not changing airplane mode or anything. Now I will try without SIM card. I will try to get into touch with our corporate t-mobile associate... Can we pinpoint if its t-mob (SIM) or something to do with LG?

Same here, G7 bought through TMobile Netherlands. I had turned it on airplane mode before going to bed, and when I tried to put airplane mode off it got stuck.
I'm waiting for the battery to die so I can try to wipe the cache...

Flash back to V10F did not help. More accurately until I insert sim (T-mobile) it looks like it works, after inserting sim freezes and resumes bootloop

Okay, out of the blue when in my pocket I noticed my phone was very hot and appeared, also without warning, stuck in a boot loop. Also on T-mobile...I had no problems before.
***Edit*** For the record I run a stock phone/firmware that I have never tempered with...

g8 (att) bootloop

Hey hey people. Been around this site for years since i had my htc mogul i believe. I searched for some help with the issue im having and came up empty. I have an lg g8 thinq and it took an update late sunday when i was asleep so i dont know when. It immediately was acting funky and by the end of day - up until this moment it has been boootlooping i even fac reset and it isnstill bootlooping-brought to att and their hands are tied talk to lg or assurion (boy they really are jelpful there.....) anyone out there experiencing this because its my primary phone qnd as i sit typing this im on my old s8 qctive that is beat to **** but pulled the sim from my g8 and stuck it in here. Anyway it will get past the lg logo and start bootlooping at the att circle/emblem-every time until the battery dies. Hopefully i didnt break amy rules again i havent been on in awhile but this really is beyond frustrating my whole life in that phone and idk last time i backed it up but its been awhile. THANK YOUA to ANYONE that can help point me in righht direction. Also i forgot to mention non rooted completely stock.

So you've already held power and volume down at the same time with the phone on?

I am too having the same problem. Mine is a T-Mobile LG G8, stock non rooted, got updated last week and then acted funny(some apps crashed), I restarted it won't reststart; Stucked on some LG-G8 screen. I hard reset it (Vol Down-Power/LG Screen, release and then hold power button; and then hard reset), After that: it stuck on boot loop.
What I can try next?

Swizzle82 said:
So you've already held power and volume down at the same time with the phone on?[/QUOTe
Yes. Dozens of times
Click to expand...
Click to collapse

When my update came through on T-Mobile it got stuck at the Tmo splash screen. Pressed the power and volume down until it turned black and let go. It rebooted normally after.

Swizzle82 said:
When my update came through on T-Mobile it got stuck at the Tmo splash screen. Pressed the power and volume down until it turned black and let go. It rebooted normally after.
Click to expand...
Click to collapse
Hi guys, am just a newbie here from Malaysia and a new owner of a 2nd hand LG G8 ThinQ (LM-G820UM); no idea where it's from but got it already with Android 10 update.
'twas working perfectly fine for a few days, but suddenyl got stuck in bootloop after I reboot (Power + Volume Down buttons) the phone when I was trying to change to a different SIM card. It would remain in bootloop until the battery is drained.
I can connect it to my laptop and seems to be detected pretty good and able to switch to Download Mode, but can't re-flash with either Flash Tool or LGUP.
- Have tried to use different Flash Tool versions - in version 2014, the flashing will just stop at server error, in 2016 and 2025 versions it will require LGST login (apparently to connect to some server which require registration).
- same goes true for LGUP, both versions 1.14 and 1.16 (patched version) will just stop at 4% then the apps will close without any error or anything happening in the phone.
Appreciate any help to recover this phone which I paid for a few hundred dollars as I was impressed with the spec and was so delighted to a very good spec phone; then this happened.
Thanks!

Jung1875 said:
I am too having the same problem. Mine is a T-Mobile LG G8, stock non rooted, got updated last week and then acted funny(some apps crashed), I restarted it won't reststart; Stucked on some LG-G8 screen. I hard reset it (Vol Down-Power/LG Screen, release and then hold power button; and then hard reset), After that: it stuck on boot loop.
What I can try next?
Click to expand...
Click to collapse
I'm in the same boat but with ATT. LM-G820UM I believe. Completely stock software. I just had it sitting on the charging dock for a while and I came back to it and it was stuck in a bootloop. No idea what's caused it, but I can't seem to get it to stop for anything. This is one of the many reasons I find not having a removable battery deeply upsetting :/

okay will try that as soon as i can get this thing to boot normal again it now stuck on the lg g8s screen think i flashed the wrong abl_a and abl_b files

Has there been any progress in getting this fixed?

Other than flashing the entire stock kdz not sure what else can be done...