Device in Fastboot mode not recognized at all as USB device - LG G5 Questions & Answers

Hey everyone,
im trying to unlock the bootloader of my LG G5, but am unable to do so as the phone is not detected at all when in fastboot mode.
While it is recognized just fine as an adb device, after rebooting into fastboot mode via adb reboot bootloader it is not recognized as an USB Device in Windows (The device manager does not show any device with wrong drivers and does not react to replugging the device). I also tried it on a different machine with the same results.
Ubuntu also does not recognize the device at all, lsusb does not output the device anywhere. It also does get recognized as an adb device when booted up normally.
I installed the necessary (I tried LG and Google) drivers and tried different USB ports (2.0 and 3.0) and cables. The phone just is not noticed as an usb device at all when in fastboot mode.
Could this be due to a broken usb port? Which seems odd because the phone is recognized when not in fastboot mode.
What else could cause this weird behaviour?
Thank You!

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Just to be clear. After you booted into fastboot mode, did you try
Code:
fastboot devices
and it just showed nothing?

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holgers0n said:
Hey everyone,
im trying to unlock the bootloader of my LG G5, but am unable to do so as the phone is not detected at all when in fastboot mode.
While it is recognized just fine as an adb device, after rebooting into fastboot mode via adb reboot bootloader it is not recognized as an USB Device in Windows (The device manager does not show any device with wrong drivers and does not react to replugging the device). I also tried it on a different machine with the same results.
Ubuntu also does not recognize the device at all, lsusb does not output the device anywhere. It also does get recognized as an adb device when booted up normally.
I installed the necessary (I tried LG and Google) drivers and tried different USB ports (2.0 and 3.0) and cables. The phone just is not noticed as an usb device at all when in fastboot mode.
Could this be due to a broken usb port? Which seems odd because the phone is recognized when not in fastboot mode.
What else could cause this weird behaviour?
Thank You!
Click to expand...
Click to collapse
Do you have usb debugging on because some devices require it to be on in order to be able to use fastboot on the computer.

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In addition to ADB and Fastboot you have to install the "Android USB Driver" that is suitable to your phone, too, to get Fastboot working.

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I forgot to mention that, oem unlock and USB debugging is enabled.
I tried installing the LG and android USB driver. But there is no way I can install these drivers to my fastboot device, as it is not recognized as an USB device at all, its like I'm plugging an USB cable with nothing attached to it into the computer.
QUOTE="User699, post: 84602251, member: 11475773"]
Just to be clear. After you booted into fastboot mode, did you try
Code:
fastboot devices
and it just showed nothing?
[/QUOTE]
Fastboot devices does not show anything.

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holgers0n said:
I tried installing the LG and android USB driver. But there is no way I can install these drivers to my fastboot device, as it is not recognized as an USB device at all, its like I'm plugging an USB cable with nothing attached to it into the computer.
Click to expand...
Click to collapse
The "Android USB Driver" is a Windows OS driver, hence it must get installed in Windows OS.

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jwoegerbauer said:
The "Android USB Driver" is a Windows OS driver, hence it must get installed in Windows OS.
Click to expand...
Click to collapse
Yes i am aware of that. As mentioned i installed the driver, my phone is recognized as an adb device. I have seen some solutions suggesting installing the driver manually when the fastboot device is not recognized correctly but the device is not recognized at all. I also tried installing the drivers as legacy hardware (Android ADB interface, Android Bootloader Interface etc.) via device manager, which results in an error ( error code 10, device can not be started)

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No more clues by me.

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@holgers0n
I tried lsusb on my Xiaomi (I don't have lg) and it worked in fastboot also.
Since it doesn't show anything if you do fastboot devices, you could try to do the standard things:
1) Change usb port on your computer
2) Try another cable
3) If it's a usb type c, plug it into your smartphone, try if it works and if it doesn't, try around that cable and retry.
I am not 100 % sure but since you said
Ubuntu also does not recognize the device at all, lsusb does not output the device anywhere. It also does get recognized as an adb device when booted up normally.
Click to expand...
Click to collapse
maybe you need to install non-free firmware as well.

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I also had same issue. my redmi note 6 pro and asus zenfone max pro m1 can be detected in adb but not in fastboot. tried everything. changing driver/disble signature verification. also tried virtual box ubuntu/window 7. but not succeeded. It is actually an issue with usb 3. so I bought usb 2 hub. now everything works fine.

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Narrry84 said:
I also had same issue. my redmi note 6 pro and asus zenfone max pro m1 can be detected in adb but not in fastboot. tried everything. changing driver/disble signature verification. also tried virtual box ubuntu/window 7. but not succeeded. It is actually an issue with usb 3. so I bought usb 2 hub. now everything works fine.
Click to expand...
Click to collapse
I'm also having the same issue with my Poco F1, it is recognized just fine as an ADB device, but not in fast boot mode. My laptop has both USB 2.0/3.1 ports hence I tried both but the result was just the same not recognised in fastboot mode
holgers0n said:
I also tried installing the drivers as legacy hardware (Android ADB interface, Android Bootloader Interface etc.) via device managerr, which results in an error ( error code 10, device can not be started)
Click to expand...
Click to collapse
yea I also manually installed USB drivers for my Poco F1 but in my case, I had no error

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The same thing is happening to me on my LG g5, did you find a solution?

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akashrathi7978 said:
I'm also having the same issue with my Poco F1, it is recognized just fine as an ADB device, but not in fast boot mode. My laptop has both USB 2.0/3.1 ports hence I tried both but the result was just the same not recognised in fastboot mode
yea I also manually installed USB drivers for my Poco F1 but in my case, I had no error
Click to expand...
Click to collapse
try linux, same thing has happened to me.

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sanfi9 said:
The same thing is happening to me on my LG g5, did you find a solution?
Click to expand...
Click to collapse
try it on linux, install adb on linux and run "fastboot devices" I used to have the same problem.

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akashrathi7978 said:
I'm also having the same issue with my Poco F1, it is recognized just fine as an ADB device, but not in fast boot mode. My laptop has both USB 2.0/3.1 ports hence I tried both but the result was just the same not recognised in fastboot mode
yea I also manually installed USB drivers for my Poco F1 but in my case, I had no error
Click to expand...
Click to collapse
Have you tried linux?

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hellofriendlymanveriosns said:
Have you tried linux?
Click to expand...
Click to collapse
No, but i got it fixed with this AMD FASTBOOT FIX guide as i was using AMD Ryzen 5 5500U.
My laptop have both USB 2.0/3.1 ports hence it worked for me on USB 2.0 port (otherwise buy a USB 2.0 hub) after running that ".bat" file as "admin" it recognised my phone.
Keep in mind i uninstalled all 3rd party "adb tools" then rebooted my laptop and used Google's official Adb tool (approx 12mb) then ran "cmd" on the same path (keep the adb tool in :c drive)

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akashrathi7978 said:
No, but i got it fixed with this AMD FASTBOOT FIX guide as i was using AMD Ryzen 5 5500U.
My laptop have both USB 2.0/3.1 ports hence it worked for me on USB 2.0 port (otherwise buy a USB 2.0 hub) after running that ".bat" file as "admin" it recognised my phone.
Keep in mind i uninstalled all 3rd party "adb tools" then rebooted my laptop and used Google's official Adb tool (approx 12mb) then ran "cmd" on the same path (keep the adb tool in :c drive)
Click to expand...
Click to collapse
STEPS I did to solve this issue on my Laptop with AMD CPU
🗃️POCO F1 Ultimate Collection & Guides📚
Welcome to POCO F1 Ultimate Collection! 🗃️ (beryllium) OFFICIAL STOCK MIUI ROM ©️ You can check my Guides for installation. Recovery ROM V12.0.3.0.QEJMIXM Fastboot ROM V12.0.3.0.QEJMIXM POCO F1 Global Stable ROM Library / POCO F1 MIUI...
forum.xda-developers.com

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holgers0n said:
Hey everyone,
im trying to unlock the bootloader of my LG G5, but am unable to do so as the phone is not detected at all when in fastboot mode.
While it is recognized just fine as an adb device, after rebooting into fastboot mode via adb reboot bootloader it is not recognized as an USB Device in Windows (The device manager does not show any device with wrong drivers and does not react to replugging the device). I also tried it on a different machine with the same results.
Ubuntu also does not recognize the device at all, lsusb does not output the device anywhere. It also does get recognized as an adb device when booted up normally.
I installed the necessary (I tried LG and Google) drivers and tried different USB ports (2.0 and 3.0) and cables. The phone just is not noticed as an usb device at all when in fastboot mode.
Could this be due to a broken usb port? Which seems odd because the phone is recognized when not in fastboot mode.
What else could cause this weird behaviour?
Thank You!
Click to expand...
Click to collapse
Hello I have exactly the same problem. I know all the right drivers are installed, because I already flashed it from CN Rom to EEA ROM a few weeks ago. Usb debugging is activated, bootloader unlocked, etc . Nothing works.
Have you resolved the problem since?

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Had the same problem after running:
adb reboot bootloader
Tried to run a fastboot command e.g. `fastboot getvar unlocked`, it gave the message `< waiting for any device >`
Solution
Assuming you have the bootloader driver installed, but its not connecting.
After running " adb reboot bootloader " with the device plugged in and in the bootloader follow these steps.
Open Device Manager => Win + R => devmgmt.msc .
Find the device called Android that has a yellow warning sign on it.
{
"lightbox_close": "Close",
"lightbox_next": "Next",
"lightbox_previous": "Previous",
"lightbox_error": "The requested content cannot be loaded. Please try again later.",
"lightbox_start_slideshow": "Start slideshow",
"lightbox_stop_slideshow": "Stop slideshow",
"lightbox_full_screen": "Full screen",
"lightbox_thumbnails": "Thumbnails",
"lightbox_download": "Download",
"lightbox_share": "Share",
"lightbox_zoom": "Zoom",
"lightbox_new_window": "New window",
"lightbox_toggle_sidebar": "Toggle sidebar"
}
Open the properties and hit update driver.
Select "Browser my computer for drivers"
Select "Let me pick from a list..."
Select "Android Device"
(If this option doesn't show up, then you don't have the drivers installed)
Select Android Bootloader Interface
(If this option doesn't show up, then you don't have the drivers installed)
Click next and the the bootloader driver should be working.
This solution does need to be repeated when ever the device goes into bootloader mode i.e. when you want to run fastboot commands.

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Mmm, just stumbled here to say that I had this problem since loong ago I unlocked the bootloader of my Z2121, and didn't know why. The reason is that I was using the Minimal ADB and Fastboot tool, because after reading the threads Bootloader driver issues on Windows 10? and [Tool] Latest ADB Fastboot and USB Driver installer tool for Windows subsequently, and of course using fawazahmed0's Latest ADB Installer, my problem was solved.
The BAT installer in the thread downloads the actual BAT installer file whose download path you can find inspecting it, and that other actual installer file for now sets the installation folder name as "platform-tools", and also adds its path into your system's user Path variable to allow running ADB and Fastboot commands from whatever folder location. For this reason you must also change the Path variable along with the folder's name if you wish to do so, or edit and modify the actual installation BAT file to change the folder name (there are a few entries).
Hope this is of help.