Develop Bugs

LG G4 Stuck in Fastboot

Hello!
I'm trying to fix a LG G4 that goes straight into fastboot mode when it's powered up.
I've tried several things:
1. Holding power + volume down. It goes into recovery mode but when I click yes to restoring everything, it automatically takes me back to the same fastboot screen.
2. I've installed Android-SDK and updated drivers when I plugged in the phone. When I put in 'adb devices', there is nothing. When I put in 'fastboot devices', the serial number shows up. The bootloader is locked and when I put in 'adb reboot bootloader', it says 'error: no devices/emulators found'. Then I tried both 'fastboot oem unlock' and 'fastboot flashing unlock', it gives me: 'FAILED <command write failed <Unknown error>>.
3. I've downloaded TWRP but it obviously does not do anything right now with my errors.
I unplugged the phone from the computer and now it says 0% battery, it does not charge.
I'm really confused and lost at what to do. Any help would be appreciated.
Thank you in advance!

JennV123 said:
Hello!
I'm trying to fix a LG G4 that goes straight into fastboot mode when it's powered up.
I've tried several things:
1. Holding power + volume down. It goes into recovery mode but when I click yes to restoring everything, it automatically takes me back to the same fastboot screen.
2. I've installed Android-SDK and updated drivers when I plugged in the phone. When I put in 'adb devices', there is nothing. When I put in 'fastboot devices', the serial number shows up. The bootloader is locked and when I put in 'adb reboot bootloader', it says 'error: no devices/emulators found'. Then I tried both 'fastboot oem unlock' and 'fastboot flashing unlock', it gives me: 'FAILED <command write failed <Unknown error>>.
3. I've downloaded TWRP but it obviously does not do anything right now with my errors.
I unplugged the phone from the computer and now it says 0% battery, it does not charge.
I'm really confused and lost at what to do. Any help would be appreciated.
Thank you in advance!
Click to expand...
Click to collapse
i dont know what fast boot means or is. but couldnt you just enter download mode and flash KDZ?

raptorddd said:
i dont know what fast boot means or is. but couldnt you just enter download mode and flash KDZ?
Click to expand...
Click to collapse
Hi! I did try to follow the guide to KDZ on here but I can't get into download mode. I'm literally stuck; the phone simply starts up right into fastboot mode.

I need to know the history. What model. What were you doing to get stuck in fastboot.

TheMadScientist420 said:
I need to know the history. What model. What were you doing to get stuck in fastboot.
Click to expand...
Click to collapse
Hi! It's the H810 model. My dad was watching YouTube videos when his phone suddenly turned black and went into fastboot. The phone was originally from Wind Mobile but my brother unlocked it through the web. My dad uses ChatR. In order to start up the phone now, I have to plug it to a wall outlet before it starts up into fastboot. When I plug it into my computer directly, it says 0% battery but it does not charge up.

I know a fastboot usb cable force charges. But it sounds like a more sisnister problem if its like u say. Id sent it to lg for waranty on bootloop issue

LG-H810 Qualcomm 9008
TheMadScientist said:
I know a fastboot usb cable force charges. But it sounds like a more sisnister problem if its like u say. Id sent it to lg for waranty on bootloop issue
Click to expand...
Click to collapse
Sir i ended up flashing wrong kdz to H810 and after flashing it become dead state (Qualcomm9008) mode i successfully recovered it by following this guide https://forum.xda-developers.com/att-g4/general/unbrick-9008-mode-h810-100-method-t3555231/page10
but now it won't go To DOWNLOAD MODE it goes To fastboot mode instead i've tried deffirent LAF.imges but no success !
here is what is on the phone screen when i connect it to pc!
(Product name-msm8992_spr_us
Variant msm8992_p1_spr_usToshiba 32GB
bootloader version -
basevand version -
serial number- LGLS991b77257e1
signing production
secureboot disabled
lock state-locked
can u help?
please (thanx)

And another one who converted his device by using qfil..
Sent from my LG-H815 using XDA Labs

JennV123 said:
Hello!
I'm trying to fix a LG G4 that goes straight into fastboot mode when it's powered up.
I've tried several things:
1. Holding power + volume down. It goes into recovery mode but when I click yes to restoring everything, it automatically takes me back to the same fastboot screen.
2. I've installed Android-SDK and updated drivers when I plugged in the phone. When I put in 'adb devices', there is nothing. When I put in 'fastboot devices', the serial number shows up. The bootloader is locked and when I put in 'adb reboot bootloader', it says 'error: no devices/emulators found'. Then I tried both 'fastboot oem unlock' and 'fastboot flashing unlock', it gives me: 'FAILED <command write failed <Unknown error>>.
3. I've downloaded TWRP but it obviously does not do anything right now with my errors.
I unplugged the phone from the computer and now it says 0% battery, it does not charge.
I'm really confused and lost at what to do. Any help would be appreciated.
Thank you in advance!
Click to expand...
Click to collapse
Try to type into the terminal: 'fastboot continue'. This should make the system start up.

JennV123 said:
Hello!
I'm trying to fix a LG G4 that goes straight into fastboot mode when it's powered up.
I've tried several things:
1. Holding power + volume down. It goes into recovery mode but when I click yes to restoring everything, it automatically takes me back to the same fastboot screen.
2. I've installed Android-SDK and updated drivers when I plugged in the phone. When I put in 'adb devices', there is nothing. When I put in 'fastboot devices', the serial number shows up. The bootloader is locked and when I put in 'adb reboot bootloader', it says 'error: no devices/emulators found'. Then I tried both 'fastboot oem unlock' and 'fastboot flashing unlock', it gives me: 'FAILED <command write failed <Unknown error>>.
3. I've downloaded TWRP but it obviously does not do anything right now with my errors.
I unplugged the phone from the computer and now it says 0% battery, it does not charge.
I'm really confused and lost at what to do. Any help would be appreciated.
Thank you in advance!
Click to expand...
Click to collapse
Just type "fasboot reboot" ..it should boot normally or just press power button for 10 seconds and release

Need help! Bootloader / fastboot unknown issue!

Hi everyone,
I´ve been trying to install twrp recovery in my Huawei Ascend P6 via fastboot. I followed this "techglen adb and fastboot guide"
I already installed everything needed for adb conection.
So I connect my phone in MTP mode and use "adb devices" and my device appears normally, but the problem happens when I reboot into Bootloader/Fastboot mode and use "Fastboot devices" it appears a device conected but with a bunch of "?????" and a smiley face at the end like this:
C:\Fastboot>adb devices
List of devices attached
123456789 device --------> bunch of numbers appear normally
C:\Fastboot>adb reboot bootloader --------> Phone restarts into bootloader mode (shows huawei ascend logo)
C:\Fastboot>fastboot devices
????????_?_???_?<??????? fastboot ----------> WTF (this is exactly what appears)
I would like to know if there's something wrong with my phone
Should I proceed and flash the custom recovery?
I have stock android 4.4.2 (rooted with kingroot) and stock recovery.
I am a total noob at this so I need your help :crying: I dont want to do anything stupid. (If already did let me know lol)

I have the same issue. Problem is that phone is bricked, so I can only enter in recovery (official, unrooted, unlocked) and fastboot mode.
Have you managed to solve or have some hint?

I have experienced a inconsistency while using minimal adb and fastboot. While device not showing i could send command and the phone would respond. After going into bootloader and while my device wasn't shown in the list i could flash twrp without much trouble, helped me go back from being stuck on bootanimation. used the command fastboot flash recovery xxxx.img (where xxx is the name recovery name). If you can get into boot loader try fastboot reboot bootloader and if the phone responds you might be in the same situation i was.
Always remember: Messing with recoveries bootloaders and boot images might make your phone unusable so do it at your own risk

Have you actually tried to flash twrp? Did you put the img file of twrp to the minimal adb and fastboot folder? If so, try the commands 'fastboot flash recovery recovery_twrp.img(<-- use the name of twrp file here, so not the exact name wrote here) and reboot. My phone is a bunch of question marks as well and it flashed twrp just perfectly (I got it frome here: http://forum.xda-developers.com/showthread.php?t=2632542)

fastboot never start after update to android 6

Hy
I had an unlocked bootloader phone. Yesterday I flashed the new Android 6, Europe version from the Huawei blog forum, no beta, on my Huawei GX8. I used the method, dload on SD card, Phone off an the press Volume down+volume up+Power button.The flashing was normaly.
Now the phone starts normaly but I can´t start fastboot. When the phone is off and i press Vol down + Power the phone start the android system and the Huawei logo is coming not the fastboot Modus. I can see my phone and the order under Windows but i can not control my phone with the fastboot command. (example: fastboot device. the answere ist searching devices, but it comes no resolution) I loaded the last version of Fastboot, but the problem is the same.
Please can you help me. What can i do? Many thanks for your help!

Should be connect the charger cable to the phone.
charger or computer
excuse me for bad english

No i use a data cable, debugging is on. I can copy data from my phone to PC or from PC to phone, but fastboot does not found my device.

bertl237 said:
No i use a data cable, debugging is on. I can copy data from my phone to PC or from PC to phone, but fastboot does not found my device.
Click to expand...
Click to collapse
And when you use adb to reboot to bootloader, what happen? Do you have "Minimal adb and fastboot tool" installed?

krispin said:
And when you use adb to reboot to bootloader, what happen? Do you have "Minimal adb and fastboot tool" installed?
Click to expand...
Click to collapse
Sorry for my question, what´s the differents about adb and fastboot tool? I have install the last version of minimal adb and the fastboot tool, also the Windows driver for the phone. Debugging is on. I try to connect my phone about the fastboot terminal. When i try to set the phone into the bootloader mod with the fastboot terminal and the equivalent command, fastboot say´s "searching phone". My phone does not react.

bertl237 said:
Sorry for my question, what´s the differents about adb and fastboot tool? I have install the last version of minimal adb and the fastboot tool, also the Windows driver for the phone. Debugging is on. I try to connect my phone about the fastboot terminal. When i try to set the phone into the bootloader mod with the fastboot terminal and the equivalent command, fastboot say´s "searching phone". My phone does not react.
Click to expand...
Click to collapse
So, you connect your phone, open minimal adb and fastboot too, run "adb devices", you see device id? If yes, run "adb reboot bootloader" . Phone shoult reboot to fastboot mode. Then run "fastboot devices" to see if it is connected properely.

i did it, like you described, but i see not my device id. Only the note "seach device"
Is it possible that TWRP is defect on my device? Is TWRP necessary for fastboot or only for root?

bertl237 said:
i did it, like you described, but i see not my device id. Only the note "seach device"
Is it possible that TWRP is defect on my device? Is TWRP necessary for fastboot or only for root?
Click to expand...
Click to collapse
No, you should be able to use adb and fastboot with stock recovery.
After first adb command you shoult approve authorization on your phone.

Here is screenshot from minimal adb...
Phone must be in MTP mode.

And here is phone in fastboot

Many thanks for your help, now I m in my bootloader.
2 problems i had.
1. My daemon was not started correctly, i have not seen my device.
2. I used the wrong command. I started with fastboot, not with the command adb device. I tap „fastboot reboot-bootloader“,but the correct command is “adb reboot-bootlader“
Now i have seen my phone is unlocked, i hope i can root my android 6.

bertl237 said:
Many thanks for your help, now I m in my bootloader.
2 problems i had.
1. My daemon was not started correctly, i have not seen my device.
2. I used the wrong command. I started with fastboot, not with the command adb device. I tap „fastboot reboot-bootloader“,but the correct command is “adb reboot-bootlader“
Now i have seen my phone is unlocked, i hope i can root my android 6.
Click to expand...
Click to collapse
Just reboot to fastboot and flash surdu-petru version of TWRP recovery 3.0.2 with command "fastboot flash recovery xxxxx.img". And than reboot to recovery and flash supersu zip.

fastboot not detecting phone

hello all,
I am trying to install android 2.0 preview. I installed android studio and I am able to get device listed using "adb devices" command.
I am able to enter boot loader using "adb reboot-bootloader" as well.
but in boot loader when I try to run fastboot oem then it says "waiting for an device".
also "fastboot devices" does not return anything.
E:\Android\sdk\platform-tools>fastboot oem unlock
< waiting for any device >
I can see "Kedacom USB device" is installed while in bootloader mode. can anyone help me? thanks
I am using windows 10

Same here, not detected by '
Code:
adb devices
' or '
Code:
fastboot devices
'. Windroid toolkit stuck at "rebooting device" while it is in Fastboot mode, and if you reboot it manually, it gets stuck at "unlocking device". Drivers are installed, maybe not properly?not properly?

adb devices works for my case after downloading latest sdk. but fastboot is no go.

windows xp ???

Sorry forgot to add that details - windows 10

Have you found a way to resolve this?

"fastboot devices" works, but any other fastboot command hangs

All fastboot commands I'm trying hang immediately without any progress or status information shown.
Only "fastboot devices" works, and reports the phone with its serial number. (When booted up to bootloader).
Could you please help me understand or analyze what the problem is, or point me to a howto? I couldn't find anything that helped me.
I was previously using LineageOS Nougat. I want to switch to a different ROM and did a full system reset (from within OS settings).
I already had TWRP 3.1.1 installed. I can still boot TWRP fine. Already tried an advanced full wipe.
I tried to use "sudo fastboot flash recover twrp.img" to flash an update, but fastboot simply sits there and does nothing.
Also tried some other fastboot commands, like "fastboot flashing unlock", or "fastboot getvar test", everything stuck and silent.
(Using a debian 9 based Linux system, fastboot version 7.0.0+r33-1, running all commands as root)
I used "adb push" to transfer an updated twrp.img version 3.3.0, and installed it from within TWRP, that worked fine, booting recovery shows that version. But didn't help for my fastboot issue.
FWIW, the device displays the following information when booting into bootloader:
(in red color): AP Fastboot Flash Mode (Secure)
BL: C1.12, 2017
Baseband: M8953.... ADDISON_ROWDSDS_CUST
Product: addison XT1635-02 32GB P7
Serial...
CPU MSM8953
eMMC...
DRAM...
Console NULL
Tools Mode config: disabled
Battery OK
flashing_unlocked
Software Status: official
Connect USB data cable
Thanks for your help

Tried ubuntu bionic with fastboot version 8.1.0, same results.

Looks like the issue is that I'm using Qubes OS. Attaching the USB device to the VM seems to have been insufficient. I used another computer which uses debian natively, and on that one "fastboot getvar all" works immediately.

If it were me, I would RSDlite 8.0.0, and proceed from there - this gets you latest bootloaders - flash TWRP 323 or whatever, flash a custom ROM, decrypt it per
https://forum.xda-developers.com/moto-z-play/how-to/mini-guide-how-to-crypt-phone-easy-t3909044
and then boot your custom ROM and set it up.