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[Q] Nexus S not appearing in device manager in fastboot

I'm attempting to flash clockwork recovery and can't get the phone to respond to fastboot devices when in fastboot mode. I've tried everything I can find with regards to the drivers (pdanet, usbdeview, etc) and I can get google's and pdanet's drivers working fine with the phone booted normally (responds to adb devices). The problem seems to be that windows appears not to even notice that the phone is plugged in in fastboot mode and does not appear in the device manager, making the manual installation of drivers an impossibility.
Anyone know how to fix this?

stoo said:
I'm attempting to flash clockwork recovery and can't get the phone to respond to fastboot devices when in fastboot mode. I've tried everything I can find with regards to the drivers (pdanet, usbdeview, etc) and I can get google's and pdanet's drivers working fine with the phone booted normally (responds to adb devices). The problem seems to be that windows appears not to even notice that the phone is plugged in in fastboot mode and does not appear in the device manager, making the manual installation of drivers an impossibility.
Anyone know how to fix this?
Click to expand...
Click to collapse
in the main setting, application, developer settings.. is usb debugging enabled?

stoo said:
I'm attempting to flash clockwork recovery and can't get the phone to respond to fastboot devices when in fastboot mode. I've tried everything I can find with regards to the drivers (pdanet, usbdeview, etc) and I can get google's and pdanet's drivers working fine with the phone booted normally (responds to adb devices). The problem seems to be that windows appears not to even notice that the phone is plugged in in fastboot mode and does not appear in the device manager, making the manual installation of drivers an impossibility.
Anyone know how to fix this?
Click to expand...
Click to collapse
When I first set up ADB and Fastboot on my pc, I was getting a response when writing 'adb devices' in the console. However, 'fastboot devices' returned absolutely nothing.
Solution (with phone connected to pc and usb debugging cheched):
1-shut down the phone
2-press and hold Volume Up key + Power
3-once in bootloader interface, in the pc command prompt, type 'fastboot devices'.
Voila!
By the way, don't mount the phone as usb storage device.

Thanks for the responses guys but yes, USB debugging is enabled and yes, I've used that way to get to fastboot mode as well as adb reboot bootloader

Hi stoo
I have a same issue - did you managed to find solution for yours?
Cheers,
Wiktor

vstar said:
Hi stoo
I have a same issue - did you managed to find solution for yours?
Cheers,
Wiktor
Click to expand...
Click to collapse
easy way to set up fastboot

Any solution
Have the same problem: locked bootloader, not rooted 4.1.2. In ADB everything is ok, drivers ok (in device manager), can get it through "adb devices". But when I boot in fastboot (adb reboot bootloader), I hear the ti-da windows sound (usb unpluged - from adb session), but no ta-di when the phone re-boot in fastboot. No exclamation mark in device manager, nothing. The USB receive nothing when in fastboot. Is it possible that the fastboot image is corrupted? Can I reflash it? Or any other advice?
Thanks
EDIT - SOLVED - at least this step
The problem was the famous "broken power button"! I knew that I had problems with the power button (didn't work - that's why I try to flash a rom (4.2.1 or customized) with sleep tile in notification area).
I thought that the button is all the time OFF and don't switch to ON, but I finally understood that when when I boot in fastmode it freeze before installing device on the PC (I also had no volume up / down navigation in fastboot, a sign that it was frozen). So I ended to consider that the power button was permanently in ON position. I opened my phone and I measure the impedance on the power button. I had ~ 4ohms in off position of the button and 1.8 ohms (cheap multimetter.... probably should be almost 0) in on position. I measured also on volume switch where I had ~ infinite on off position, so I concluded that the button if blocked. I tried to see if I can resurrect it but no choice, so I took it off (unsoldered). I put the battery and the USB cable and boot it. From ADB I reboot it in fastboot and voila! The device popped in device manager! One problem solved! BUT...
I tried to use the Nexus Root Toolkit and it boots in fastmode and try to unlock the bootloader, but it asked me on phone screen if I agree for unlocking. I was able to use the volume to select Yes but I couldn't choose it with power! I had no option but to take the battery off. Starting from that point it was almost impossible to power it again. When I plugged the USB it shown the battery icon (charging). I tried every trick that I found on web, but nothing worked (even to fast plug / unplug many times the USB to overcharge it, but nothing). I was able only by pressing on the middle of volume (so Up and DOWN in the same time) and plus the USB to get to the screen of unlocking bootloader, but without the options YES/NO on the screen. Seems that it saves this state between boots, but why no option? Finally I was unable to boot at all, and it is like totally bricked
I thought that the power button is a simple switch ON / OFF, so I soldered 2 wires and I tried to touch them (short circuit) to simulate the ON, but nothing happened. Is it the button more complex that a simple switch? no ideea...
So now have a better phone than before (at least theoretically it should be able to fastboot), but it values zero because I can't power it on....

OK So I am in the exact same situation.
Nexus S, Broken power button, adb can see the device, fastboot cannot. fastboot cannot be navigated with the volume keys.
I also want to put an other rom onto it, but firstly I want to put TWRP recovery on it, as it supports touch, CW needs the power
button which like mentioned does not work.
I would rather not unsolder my power button to get into fastboot, any suggestions on how that might still be achieved?
thx
catalinu said:
Have the same problem: locked bootloader, not rooted 4.1.2. In ADB everything is ok, drivers ok (in device manager), can get it through "adb devices". But when I boot in fastboot (adb reboot bootloader), I hear the ti-da windows sound (usb unpluged - from adb session), but no ta-di when the phone re-boot in fastboot. No exclamation mark in device manager, nothing. The USB receive nothing when in fastboot. Is it possible that the fastboot image is corrupted? Can I reflash it? Or any other advice?
Thanks
EDIT - SOLVED - at least this step
The problem was the famous "broken power button"! I knew that I had problems with the power button (didn't work - that's why I try to flash a rom (4.2.1 or customized) with sleep tile in notification area).
I thought that the button is all the time OFF and don't switch to ON, but I finally understood that when when I boot in fastmode it freeze before installing device on the PC (I also had no volume up / down navigation in fastboot, a sign that it was frozen). So I ended to consider that the power button was permanently in ON position. I opened my phone and I measure the impedance on the power button. I had ~ 4ohms in off position of the button and 1.8 ohms (cheap multimetter.... probably should be almost 0) in on position. I measured also on volume switch where I had ~ infinite on off position, so I concluded that the button if blocked. I tried to see if I can resurrect it but no choice, so I took it off (unsoldered). I put the battery and the USB cable and boot it. From ADB I reboot it in fastboot and voila! The device popped in device manager! One problem solved! BUT...
I tried to use the Nexus Root Toolkit and it boots in fastmode and try to unlock the bootloader, but it asked me on phone screen if I agree for unlocking. I was able to use the volume to select Yes but I couldn't choose it with power! I had no option but to take the battery off. Starting from that point it was almost impossible to power it again. When I plugged the USB it shown the battery icon (charging). I tried every trick that I found on web, but nothing worked (even to fast plug / unplug many times the USB to overcharge it, but nothing). I was able only by pressing on the middle of volume (so Up and DOWN in the same time) and plus the USB to get to the screen of unlocking bootloader, but without the options YES/NO on the screen. Seems that it saves this state between boots, but why no option? Finally I was unable to boot at all, and it is like totally bricked
I thought that the power button is a simple switch ON / OFF, so I soldered 2 wires and I tried to touch them (short circuit) to simulate the ON, but nothing happened. Is it the button more complex that a simple switch? no ideea...
So now have a better phone than before (at least theoretically it should be able to fastboot), but it values zero because I can't power it on....
Click to expand...
Click to collapse

Yes, it should have been better for me to have also a possibility to enter in fastboot with the power button blocked in ON position, but I didn't find. And now I know no way how to power it up...

fastboot drivers
http://www.samsung.com/us/support/owners/product/GT-I9020PWAATT#
has anybody considered using this executable from samsung ..
from what i understood when installing it ,it only unzips the contents at programfiles/Samsung/drivers
then you can check this thread to install them spesifically http://forum.xda-developers.com/showthread.php?t=1901617
..In short.
Go to
"Device Manager"
find
"Android 1.0" or something like that (i had my device in fastboot/bootloader mode, dont know if it was necessary)
install drivers from the drivers directory and install
P.S. Mine is an ordinary 9023nexus s (slcd) though
be a bit more careful with nexus s4g

[Q] [A700] - Can't unlock bootloader-hangs on green Acer logo [SOLVED]

Hi All:
First-time poster here. I searched the forums but could not find an answer to my problem.
I want to root my A700 and install a custom ROM but I can't get the bootloader unlocked. I have followed the instructions from this post but can't get past the first step. ADB definitely recognizes my device [adb devices] by returning the correct s/n. When I enter [adb reboot-bootloader] my tab reboots but then hangs on the green Acer logo and goes no further. Any attempts to use ADB result in a "waiting for device" message. My only option is to power off by holding the power button then reboot normally.
Here's my device/PC info:
A700:
Android version: 4.1.1
Kernel version: 3.1.10+
Image version: Acer_AV051_A700_RV18RC01_PA_CUS1
Build Number: Acer_AV051_A700_1.052.00_PA_CUS1
PC:
Windows 8 Pro 64bit
Android SDK 64 bit (I also tried 32bit with no luck)
I have rooted devices before so I am not totally new to the process, but no expert either! Any thoughts?
Thanks in advance for any advice/info shared!
Note: Had to use Acer USB driver for ICS. There was no USB driver for JB. Could that be the problem?

Perhaps try to reboot into bootloader manualy. For this first switch off your device, then press power button and volume (-) together. As soon as the tab vibrates, release the power button and switch the screen lock two or three times. Then you should get into the bootloader mode and can try to use the adb commands. Of corse, with a connected usb cable.
Sent from my A700 using xda app-developers app

georgepcde said:
Perhaps try to reboot into bootloader manualy. For this first switch off your device, then press power button and volume (-) together. As soon as the tab vibrates, release the power button and switch the screen lock two or three times. Then you should get into the bootloader mode and can try to use the adb commands. Of corse, with a connected usb cable.
Sent from my A700 using xda app-developers app
Click to expand...
Click to collapse
Good thought but no luck.
Thanks, though.

After rebooting with "adb reboot bootloader" you should be in the bootloader, and in fastboot mode. Try issuing "fastboot devices" after rebooting.
Edit: Just tried the unlock guide from that thread, and with the ICS driver from Acer. Getting the driver to install was way worse than unlocking the bootloader (many "installations" that didn't create any files for whatever reason).
After ADB recognized my tab, I was able to follow the guide up to the "flash recovery" part.
- with "adb reboot-bootloader" you should land in the bootloader. It only shows the Acer logo and some very small written things in the upper-right corner;
- from here on you need to use fastboot: "fastboot oem unlock". Typing "fastboot devices", as I said before, works just like "adb devices";
- the whole unlocking procedure is very frustrating, because the instructions are so small and the timeout so fast. If I'm not mistaken, you need to choose with VOL- and confirm with VOL+.
PS: pmrmx was faster

rgkjr1 said:
Hi All:
First-time poster here. I searched the forums but could not find an answer to my problem.
I want to root my A700 and install a custom ROM but I can't get the bootloader unlocked. I have followed the instructions from this post but can't get past the first step. ADB definitely recognizes my device [adb devices] by returning the correct s/n. When I enter [adb reboot-bootloader] my tab reboots but then hangs on the green Acer logo and goes no further. Any attempts to use ADB result in a "waiting for device" message. My only option is to power off by holding the power button then reboot normally.
Here's my device/PC info:
A700:
Android version: 4.1.1
Kernel version: 3.1.10+
Image version: Acer_AV051_A700_RV18RC01_PA_CUS1
Build Number: Acer_AV051_A700_1.052.00_PA_CUS1
PC:
Windows 8 Pro 64bit
Android SDK 64 bit (I also tried 32bit with no luck)
I have rooted devices before so I am not totally new to the process, but no expert either! Any thoughts?
Thanks in advance for any advice/info shared!
Note: Had to use Acer USB driver for ICS. There was no USB driver for JB. Could that be the problem?
Click to expand...
Click to collapse
After the ADB reboot-bootloader, there should be some really tiny white type in the upper left corner of the green logo screen.
This is when you type "fastboot OEM unlock" then volume +, then volume -
The tiny type should change. Forever after you will have a tiny message up there about the bootloader is unlocked.

smirneger said:
After rebooting with "adb reboot bootloader" you should be in the bootloader, and in fastboot mode. Try issuing "fastboot devices" after rebooting.
Edit: Just tried the unlock guide from that thread, and with the ICS driver from Acer. Getting the driver to install was way worse than unlocking the bootloader (many "installations" that didn't create any files for whatever reason).
After ADB recognized my tab, I was able to follow the guide up to the "flash recovery" part.
- with "adb reboot-bootloader" you should land in the bootloader. It only shows the Acer logo and some very small written things in the upper-right corner;
- from here on you need to use fastboot: "fastboot oem unlock". Typing "fastboot devices", as I said before, works just like "adb devices";
- the whole unlocking procedure is very frustrating, because the instructions are so small and the timeout so fast. If I'm not mistaken, you need to choose with VOL- and confirm with VOL+.
PS: pmrmx was faster
Click to expand...
Click to collapse
pmrmx774 said:
After the ADB reboot-bootloader, there should be some really tiny white type in the upper left corner of the green logo screen.
This is when you type "fastboot OEM unlock" then volume +, then volume -
The tiny type should change. Forever after you will have a tiny message up there about the bootloader is unlocked.
Click to expand...
Click to collapse
Unfortunately, the problem is that the little white text never appears - that's where it hangs - the screen is completly blank except for the green Acer logo. And if I try to enter "fastboot devices" I simply get another adb prompt (nothing else - it just jumps to a new line.) If I enter "fastboot oem unlock", adb returns "<waiting for device>" and then goes nowhere. All the while, for both commands, the tab is stuck on the Acer logo.

rgkjr1 said:
Unfortunately, the problem is that the little white text never appears - that's where it hangs - the screen is completly blank except for the green Acer logo. And if I try to enter "fastboot devices" I simply get another adb prompt (nothing else - it just jumps to a new line.) If I enter "fastboot oem unlock", adb returns "<waiting for device>" and then goes nowhere. All the while, for both commands, the tab is stuck on the Acer logo.
Click to expand...
Click to collapse
You probably need to install adb USB drivers ( android universal USB driver I think which is different than the Acer USB driver ). While adb will work when tablet is in USB debugging mode, once it rebooted your PC can't communicate with it anymore that's why its waiting for the device.
Sent from my A701 using xda app-developers app

hey_joe said:
You probably need to install adb USB drivers ( android universal USB driver I think which is different than the Acer USB driver ). While adb will work when tablet is in USB debugging mode, once it rebooted your PC can't communicate with it anymore that's why its waiting for the device.
Sent from my A701 using xda app-developers app
Click to expand...
Click to collapse
Thanks, hey_joe. I actually already tried that but decided to try again. This time it worked! I don't know what I did differently but bootloader is now unlocked!
Thanks, All!!!

Tablet ubislate 9ci hanging on bootloading
Dear sir/madam, I am new to this forum. I purchased a new tablet Datawind Ubislate 9ci. It is a 9 inch no-bluetooth tablet.
>Details:
>*.Android 4.1.1
>*.Rock chip RK2928
>*.KERNEL linux version 3.0.36 i was trying to install CWM through mobile odin and ROM manager but my tablet was not supported so i downloaded build.prop editor from google play and changed it to some other cwm recognizable model viz. Samsung, nexus etc. When i was doing the above mentioned procedure, suddenly my tablet is coming up to bootloading and hanging there only and not opening i tried to go to recovery by pressing power and vol but i am not getting recovery menu, i also tried to hard reset by pressing reset with a needle at the back but all in vain again hanging on bootloading i also tried press and hold power & vol- and several other combinations , all in vain so kindly help me and guide me Thank you

Hello there. First of all thank you for your support. I'm here because I have the same problem as OP, but first a little context.
I have already rooted my A700 before, without any difficulties. But after a crash, I restored it to factory and tried to redo the whole procedure.
So, here I am, USB driver installed (I had to modify android_winusb manually for windows to finally accept the drivers), adb up and running, adb reboot-bootloader executed and...
Acer screen, no text, just like the OP. And a yellow "Fastboot" device in my Device Manager window. So I'm stuck here. I've tried to uninstall/reinstall the google USB drivers to no avail, unlike OP. I can access the Acer recovery with the reboot recovery prompt, but I'm not confident enough to ignore the step in this tutorial.
Additional precisions : when the device is stuck with the Acer Logo (without text) trying to use a fastboot prompt (like oem unlock) only gives me the <Waiting for device> message.
I could use the Acer recovery to install a rom from external storage, but I'm unsure if it's a good idea to NOT use CWM or TWRP
Thank you, I'm starting to miss Android 4.4 (yeah, because the Acer update manager give an error 400)
Update : I did manage to access fastboot. Just as I had to modify android_winusb with the PID of my tablet when it was running, I also had to edit the file with the PID of the tablet waiting in fastboot. I didn't noticed they were different.

[Q] no adb and fastboot access - no root possible?

Hello everyone!
I'm trying to root my Shield K1 (Android 6.0) since hours, without success because:
I have no acces via adb. Im using the latest adb and also the right drivers (see picture) but I alwas get the message "unauthorized" in adb.
I can't boot my tablet into fastboot mode. When I press the power button + volume up to come into the menu and I select fastboot protocol, the tablet just starts again into the same menu - so i don't get into the fastboot mode. Pressing the powerbutton + volume down don't works either.
I have tried already almost everything: uninstallig drivers/reinstalling it, factory reset on my K1,...
So how I can root my phone without adb or fastboot? Can anyone help?
Even the recovery mode is broken I think, after booting into it, the green android with an red triangle is shown.
Is there something wrong with my K1?
PS: In the menu, which is shown after pressing power + volume up, is standing:
[nvtboot] (version UNDEF_BUILD]
[bootloader] (version UNDEF_BUILD]
Device - locked

You need to enable USB debugging in the developer settings and then allow debugging access from your computer by accepting a popup on your tablet.

Yes, I know this and I did this of course. But there never poped up something on my tablet.
So I also resetted the debugging setting, wiped the tablet, but nothing helped.

1. Sometimes the micro USB cable you use can be bad so I would suggest trying a different cable (especially since you have a K1 which doesn't come with a charger or cable).
2. Fastboot mode is that screen with the menu, that's why "fastboot protocol" just takes you back to the same screen. Also, recovery mode on the stock tablet just shows the android icon and triangle, so your recovery mode is fine.
I would suggest booting the tablet into android (so not the fast boot or recovery mode) and connect it to the windows PC using different cables until the authorisation pop up come up.

I am having the same issues as the OP, the only difference is my bootloader says "unlocked."
I was able to get authorization from the computer, no issues there, however fastboot will not find the device and neither will adb when at the "fastboot mode."
I'm trying to get fastboot so I can flash a recovery, but no luck to this point.
Anyone have any ideas or suggestions?

fl4r3 said:
Fastboot mode is that screen with the menu, that's why "fastboot protocol" just takes you back to the same screen.
Click to expand...
Click to collapse
Thanks so much mate! :good: That's the sentence, that helped me. I didn't know this menu is already the fastboot mode. So if one know this it's quite easy to proceed.
Problem solved - tablet already rooted
The adb access is still "unauthorized" but doesn't matter anymore.

No problem, glad you you got it sorted.
It's odd your ADB access is still unauthorised, but at least it still works.

jpk17 said:
I am having the same issues as the OP, the only difference is my bootloader says "unlocked."
I was able to get authorization from the computer, no issues there, however fastboot will not find the device and neither will adb when at the "fastboot mode."
I'm trying to get fastboot so I can flash a recovery, but no luck to this point.
Anyone have any ideas or suggestions?
Click to expand...
Click to collapse
Just as an FYI....I got mine working. Needed to reinstall the nvidia drivers... Got authorization, etc... so assumed working and as we all know assuming is bad!
Sent from my wx_na_wf using Tapatalk

Nvidia Shield Tablet K1 stuck on Bootloader Info Screen / Bootloops -- Need help

Hey everyone. So some time ago I unlocked the Bootloader, rooted and flashed with custom ROM my Nvidia Shield K1 and flashed TWRP. All was going well untill I decided to flash another ROM with an app (which was stupid indeed) Long story short it seems now as if I have no ROM and no recovery and all I got is the "Bootloader info screen" or whatever its called.
So the only thing I can make it display is:
[nvtboot] (version UNDEF_BUILD)
[bootloader] (version UNDEF_BUILD)
Device - Unlocked
Serial Number xxxxxxxxxxxxxxxxxxxxxxx
Press <Power> to select [...]
Continue
Fastboot Protocol
Recovery mode
Reboot
Poweroff
1. Using Continue does nothing, just says booting failed for like 100ms and goes back to where it was.
2. Fastboot Protocol just reboots the devices to the same thing after like 2 sec
3. Recovery mode same as Fastboot Protocol
4.Reboot and Poweroff does what it says
I've tried everything I could find online with it. No physical key combination can make it boot the ROM or TWRP.
I tried adb fastbooting with minimal adb and fastboot like Ive done times before with this Shield K1 and I cant make it see this device. ( "adb devices" wont list it)
I have tried using different USB ports, usb drivers, usb cables, PCs, fastboots and reinstalled everything multiple times and nothing changes.
I tried using any and every USB driver, ADB fastbooting Nvidia offers for this device.
The PC itself seems to detect the tablet just fine. Pluggin and unpluggin results in a notification and the android device is detected in Device Manager properly.
Powering off and on the tablet also results in a notification on the PC.
I have no idea what to do at this point and my last hope is this thread.

I had the same issue. Finally decided to reflash to stock and all is well

Shield Tablet problems: ADB, Recovery Mode, Fastboot... = DEAD?

I can imagine that you all are tired of reading this headline, but seriously, ME TOO.
I have been looking for information about this issue during several weeks and I have not found any solution, so I would extremely thank you if you take your time reading this problem and trying to help me finding a solution.
Some months ago I tried to flash a ROM on my Shield Tablet, I followed all the steps from a topic in this forum: [Complete Guide] SHIELD Tablet K1 Root, Custom Rom and Xposed Framework but I wanted to try a different ROM: CARBON-CR-5.1-MOO-WEEKLY-shieldtablet-20170216-0454 (the name of the file) And now I have a tablet that is stuck on the Carbon launch screen every time I turn it on, when I press volumen down + power it goes into the screen buttt as soon as I press recovery mode the only thing it does is to restart itself and stays stuck in the NVIDIA screen. The Minimal ADB and Fastboot do not recognize the tablet with the adb devices command.
When I turn on the tablet (and stays stuck into the IOS icon as I mentioned before) and connect it to the PC the device manager recognize the tablet as a Portable device with the name: MTP USB device, when I press the power+volumen down the PC recognize the tablet as an Android Device -> Android Bootloader Interface. And this is all the information I have about my problem...
May you help me?
Thank you in advance. I hope your knowledge will help me and other people with the same problem. If you need more information of this problem let me know and I'll answer ASAP. If you have any idea tell me and I'll try it.

Warlain said:
when I press volumen down + power it goes into the screen buttt as soon as I press recovery mode the only thing it does is to restart itself and stays stuck in the NVIDIA screen. The Minimal ADB and Fastboot do not recognize the tablet with the adb devices command.
When I turn on the tablet (and stays stuck into the IOS icon as I mentioned before) and connect it to the PC the device manager recognize the tablet as a Portable device with the name: MTP USB device, when I press the power+volumen down the PC recognize the tablet as an Android Device -> Android Bootloader Interface. And this is all the information I have about my problem...
May you help me?
Click to expand...
Click to collapse
Your device is not, dead, it's only taking some time to reflect
First of all, I understood that you're able to access to the device's bootloader menu, through the button combo (black screen with white text, "continue","restart bootloader","recovery mode"), and you selected "recovery mode".
Now, unless you have flashed a custom recovery, there's nothing to do with the shield's stock recovery, so, just enter in the bootloader menu as you did, without selecting any option.
You are now in "fastboot mode", in order to check your device's connection you have to write in the adb shell
Code:
fastboot devices
If you see your device you can now boot a custom recovery that will help you to fix the problems you caused, I would follow this link: (copy-paste, can't post links)
"nvidiashieldzone.com/shield-tablet/shield-tablet-root/root-shield-tablet-v1-marshmallow/"
And do the 8th step, in "Root procedure"
Fastboot with TWRP
Type “fastboot devices” Copy and make sure your Shield Tablet is visible.
If your Shield Tablet is listed, type “fastboot boot twrp-20151227-EXPERIMENTAL-shieldtablet-m.img” Copy (or whatever you named it) and hit enter. If your TRWP image filename has a space in it, you may have issues.
After 15 seconds or so (be patient), you should see the TWRP Recovery screen. Note: This experimental version has some UI issues, just keep at it.
You may be prompted with something to do with the system being READ ONLY. Accept the default and swipe.
Click to expand...
Click to collapse

Use fastboot to wipe cache (fastboot erase cache) then try to flash TWRP (with fastboot) again. This will often clear up issues with being unable to boot to TWRP (at least on other devices).
If you are able to boot TWRP, restore the TWRP backup (if you made one) or put another ROM on the phone, and flash it.

I also have this kind of problem. After i update twrp by flashing it and restore a backup the sistem doesnt show. Stucks on nvidia logo. I tried even restore my recent backup but nothing also. Any idea ?

'Artemis' said:
Your device is not, dead, it's only taking some time to reflect
First of all, I understood that you're able to access to the device's bootloader menu, through the button combo (black screen with white text, "continue","restart bootloader","recovery mode"), and you selected "recovery mode".
Now, unless you have flashed a custom recovery, there's nothing to do with the shield's stock recovery, so, just enter in the bootloader menu as you did, without selecting any option.
You are now in "fastboot mode", in order to check your device's connection you have to write in the adb shell
Code:
fastboot devices
If you see your device you can now boot a custom recovery that will help you to fix the problems you caused, I would follow this link: (copy-paste, can't post links)
"nvidiashieldzone.com/shield-tablet/shield-tablet-root/root-shield-tablet-v1-marshmallow/"
And do the 8th step, in "Root procedure"
Click to expand...
Click to collapse
Done, Thank you a lot! It starts working again!!!