Database Info

[Q] Can't fastboot / No recovery JB

I have an interesting problem:
I have a tf300t curently running JRO03C.ww_epad-10.4.2.17-20121018
I ended up here after an unsuccessful flash with twrp. Tried to recover my back up with no joy. At this time it would only boot twrp recovery, finally flashed stock via micro sdcard and got it to boot again! Only I had no root anymore, so I tried to boot into recovery and there was none. So next I tried to boot into bootloader and when I select fastboot, the tablet says starting "starting fastboot download protocol" but after nothing else happens. ADB looses it, and it just stops right there.
The good news is that I can still use the tablet, it boots and everything works fine but I have no root. I have searched and read and searched and read. I don't know if the reflash flashes the bootloader but that didn't seam to have any effect. If anybody could point me in the right direction I would sure appriciate the help.

there is a way on the TWRP instructions using terminal when you are in system

nitsuj79 said:
I have an interesting problem:
I have a tf300t curently running JRO03C.ww_epad-10.4.2.17-20121018
I ended up here after an unsuccessful flash with twrp. Tried to recover my back up with no joy. At this time it would only boot twrp recovery, finally flashed stock via micro sdcard and got it to boot again! Only I had no root anymore, so I tried to boot into recovery and there was none. So next I tried to boot into bootloader and when I select fastboot, the tablet says starting "starting fastboot download protocol" but after nothing else happens. ADB looses it, and it just stops right there.
The good news is that I can still use the tablet, it boots and everything works fine but I have no root. I have searched and read and searched and read. I don't know if the reflash flashes the bootloader but that didn't seam to have any effect. If anybody could point me in the right direction I would sure appriciate the help.
Click to expand...
Click to collapse
I saw on another site that with this tablet it will go into fastboot but wont popup as fastboot device on your computer, but you can still use fastboot commands. worked for me

mikaole said:
there is a way on the TWRP instructions using terminal when you are in system
Click to expand...
Click to collapse
You must have root permission for that method

imp3r10 said:
I saw on another site that with this tablet it will go into fastboot but wont popup as fastboot device on your computer, but you can still use fastboot commands. worked for me
Click to expand...
Click to collapse
No when I try to flash recovery it says waiting for device and nothing ever happens.

I seamed to have got it. I down graded to 10.4.2.9 and back to 13. plugged it to the computer and this time it installed drivers and that time I was able to flash recovery. I don't know what happened and it was probably something that I was doing wrong. But just incase that is what did the trick and it helps someone else, i wanted to be sure and follow up.

[Q] stuck in boot loop / pc not recognizing phone with adb

Hi,
I tried to install a ROM but it got stuck on the white screen with the HTC logo. I tried to do factory reset but it gets stuck again. I don't have clockwork recovery, and I rooted my phone using adb and ace recovery, which is not on my phone. I only temporarily used it to flash my rom, stupid I know. :-/ When I connect my phone to the PC it is not being recognized. I tried putting the PD98IMG.zip file on my sd card but it just says that it the image is incorrect. Is there anything I can do? Is this fixable?

brickdummy said:
Hi,
I tried to install a ROM but it got stuck on the white screen with the HTC logo. I tried to do factory reset but it gets stuck again. I don't have clockwork recovery, and I rooted my phone using adb and ace recovery, which is not on my phone. I only temporarily used it to flash my rom, stupid I know. :-/ When I connect my phone to the PC it is not being recognized. I tried putting the PD98IMG.zip file on my sd card but it just says that it the image is incorrect. Is there anything I can do? Is this fixable?
Click to expand...
Click to collapse
Flash a recovery.img from fastboot. What is an ace recovery? Read my signature for the HTC logo problem.

brickdummy said:
Hi,
I tried to install a ROM but it got stuck on the white screen with the HTC logo. I tried to do factory reset but it gets stuck again. I don't have clockwork recovery, and I rooted my phone using adb and ace recovery, which is not on my phone. I only temporarily used it to flash my rom, stupid I know. :-/ When I connect my phone to the PC it is not being recognized. I tried putting the PD98IMG.zip file on my sd card but it just says that it the image is incorrect. Is there anything I can do? Is this fixable?
Click to expand...
Click to collapse
I just went through some similar stuff. What type of computer are you using? PC/Mac? Are you using the original cable? What troubleshooting steps for connectivity have you done? Different cable? USB port?
Can you access the bootloader screen when you pull the battery and reboot while holding the volume button down and holding the power button? By accident, I found that the phone and PC will communicate with each other when "Fastboot" is selected on the bootloader screen (you should hear a connection chime and it should change to "Fastboot USB") except I could only get fastboot commands to work. The good news is that should be enough to flash a boot or whatever else you need to get back in business.

shadowboxx said:
I just went through some similar stuff. What type of computer are you using? PC/Mac? Are you using the original cable? What troubleshooting steps for connectivity have you done? Different cable? USB port?
Can you access the bootloader screen when you pull the battery and reboot while holding the volume button down and holding the power button? By accident, I found that the phone and PC will communicate with each other when "Fastboot" is selected on the bootloader screen (you should hear a connection chime and it should change to "Fastboot USB") except I could only get fastboot commands to work. The good news is that should be enough to flash a boot or whatever else you need to get back in business.
Click to expand...
Click to collapse
Hi, Thanks for the reply.I am using windows 7. I downloaded the drivers for HTC, and I am using a data cable and the USB port in the back of my computer, nearest the mother board. I do see "Fastboot USB" on the phone but when i type in the command prompt "adb devices" I get nothing.

brickdummy said:
Hi, Thanks for the reply.I am using windows 7. I downloaded the drivers for HTC, and I am using a data cable and the USB port in the back of my computer, nearest the mother board. I do see "Fastboot USB" on the phone but when i type in the command prompt "adb devices" I get nothing.
Click to expand...
Click to collapse
That's great you're getting the fastboot usb message! As long as you're not using a hub or some other usb extender, any functioning usb port on the pc will do. Again, I learned this by accident (ie the hard way) and found that in this mode, only fastboot commands will work, not adb. (on a side note, and others should correct me here, adb and fastboot work together when the phone is rebooted normally or in recovery but not in the bootloader screen)
Great test for connection: fastboot devices (if you get anything else except a serial # with fastboot after it, then close the cmd window, unplug, and pull battery/reboot to bootloader), fastboot reboot-bootloader. Once it reboots back into the bootloader screen, make sure you press the power button while fastboot is selected and you should again hear the chime and see fastboot usb come up. This is your phone saying it's ready to accept your fastboot commands.
Do let us know how it works.

bananagranola said:
Flash a recovery.img from fastboot. What is an ace recovery? Read my signature for the HTC logo problem.
Click to expand...
Click to collapse
Hi I actually saw your post earlier thank you. I will work on this. I found it in a tutorial when I rooted my phone with HTC dev, ace_recovery_ext_4.img. I'll post where i found it later.

bananagranola said:
Flash a recovery.img from fastboot. What is an ace recovery? Read my signature for the HTC logo problem.
Click to expand...
Click to collapse
when i flashboot the recovery.img file it goes to the red triangle.

brickdummy said:
Hi I actually saw your post earlier thank you. I will work on this. I found it in a tutorial when I rooted my phone with HTC dev, ace_recovery_ext_4.img. I'll post where i found it later.
Click to expand...
Click to collapse
Hi the program is actually called 4EXT Recovery Touch. I finally was able to open it through fastboot....Now all thats left is to find the right zip file to put my phone back to stock.

shadowboxx said:
That's great you're getting the fastboot usb message! As long as you're not using a hub or some other usb extender, any functioning usb port on the pc will do. Again, I learned this by accident (ie the hard way) and found that in this mode, only fastboot commands will work, not adb. (on a side note, and others should correct me here, adb and fastboot work together when the phone is rebooted normally or in recovery but not in the bootloader screen)
Great test for connection: fastboot devices (if you get anything else except a serial # with fastboot after it, then close the cmd window, unplug, and pull battery/reboot to bootloader), fastboot reboot-bootloader. Once it reboots back into the bootloader screen, make sure you press the power button while fastboot is selected and you should again hear the chime and see fastboot usb come up. This is your phone saying it's ready to accept your fastboot commands.
Do let us know how it works.
Click to expand...
Click to collapse
Hi, this did work, thank you. Would you happen to know how i can load the stock software on my phone? I had it rooted before im not sure if its still rooted. I also managed to get the 4ext recovery on my phone too.

shadowboxx said:
(on a side note, and others should correct me here, adb and fastboot work together when the phone is rebooted normally or in recovery but not in the bootloader screen)
Click to expand...
Click to collapse
As far as I know, fastboot only works when your phone is in fastboot mode. ADB works in recovery or system.
brickdummy said:
Hi, this did work, thank you. Would you happen to know how i can load the stock software on my phone? I had it rooted before im not sure if its still rooted. I also managed to get the 4ext recovery on my phone too.
Click to expand...
Click to collapse
Flash a rooted stock ROM from recovery. Whether you have root is in your system partition. Whether your bootloader is unlocked is in your bootloader. Whether you have a custom recovery is in your recovery partition. Three separate things.
As for your post in your other thread, read my signature.

bananagranola said:
As far as I know, fastboot only works when your phone is in fastboot mode. ADB works in recovery or system.
Flash a rooted stock ROM from recovery. Whether you have root is in your system partition. Whether your bootloader is unlocked is in your bootloader. Whether you have a custom recovery is in your recovery partition. Three separate things.
Click to expand...
Click to collapse
I'm sorry, I have no idea what I am doing. Can you show me the steps? When I try installing a stock rom zip file in my recovery from my sd card it aborts.

brickdummy said:
I'm sorry, I have no idea what I am doing. Can you show me the steps? When I try installing a stock rom zip file in my recovery from my sd card it aborts.
Click to expand...
Click to collapse
I'm guessing that you're trying to flash a PD98IMG.zip or a RUU. You need an actual stock rooted ROM, probably from here on the forum. Or just flash Android Revolution HD, an optimized rooted stock ROM, also from here on the forum in the development section. For more specific steps read the Ace Think Tank linked in my signature.

bananagranola said:
I'm guessing that you're trying to flash a PD98IMG.zip or a RUU. You need an actual stock rooted ROM, probably from here on the forum. Or just flash Android Revolution HD, an optimized rooted stock ROM, also from here on the forum in the development section. For more specific steps read the Ace Think Tank linked in my signature.
Click to expand...
Click to collapse
Ok, one more thing. I have S-ON. does that matter?
----
It did not, lol anyway it worked. Thank you everyone for you help. I really appreciate it.
-----
For those wondering I found the stock rooted rom here http://http://forum.xda-developers.com/showthread.php?t=996368
http://forum.xda-developers.com/showthread.php?p=26617631
Instructions to flash the rom
http://http://forum.xda-developers.com/showthread.php?t=2168500

brickdummy said:
Ok, one more thing. I have S-ON. does that matter?
Click to expand...
Click to collapse
Yes. You need to read the part in my signature about being stuck in the splash screen.

bananagranola said:
Yes. You need to read the part in my signature about being stuck in the splash screen.
Click to expand...
Click to collapse
ok, got it. Thank you again

Dear friends,
I have this problem: I got a brand new TCL S720 and the Google Play did not work, being a known rom issue. So, before doing anything, I've managed to make a backup of it's original rom with MTK Droid tools whichI supose it did it well. Then I've tried to install a CWM recovery to try a custom rom for it. The CWM recovery seemed to install succesfully but I didn't manage to install the new rom. If I remember well, it stucked on boot logo. Then tried to revert at it's original stock recovery, managed to have the phone back as it was in initial state, but doing more tries, It remained stucked on boot logo. The problem is that my computer doesn't recognise it anymore, when I connect it to USB it tries to install MTP usb driver but even before the driver was installed well, now it refuse to install, like the driver is not good or the proper driver doesn't exist. So the only thing I can do is to boot on stock recovery but even I tried to copy the original rom update.zip on external SD and to flash the phone using install update from sd card in recovery mode, It doesn't find the external sd card. So I'm stuck here, the computer doesn't detect the phone to try flashing it with SP flash tool or MTK Droid tool, and I also can't flash it from sd card. Have you any idea how to make it work again?
Thanks in advance.

[Q] Unlocked, reflashed, app ran into problem phone restarted and bricked?

Hi there,
Im still kinda a noob with android...
but i managed to unlock my htc sensation trough the steps @HTC,
changed the recovery, tried to flash a rom.
it failed due to my phone not being S-off. so i flashed it back :/
no problem there i thought just a rooted htc.
downloaded an app to remove bloat. and all seemed fine...
I was playing Clash of Clans, and it gave a message that the Google play services stopped and the phone rebooted.
when booted the lock screen was frozen, i pulled out the battery to find out my phone is unresponsive..
When i connect to windows 8, it cant recognize my phone at all
When i connect it to a charger i dont see the charging light.
and the worse thing is.. i cant get into the recovery.
any idea's what i can try?
i checked out the [unbrick] tread but i cant seem to figure out which "Package" i need and the links on the bottom of the page dont work when i click them
Thanks in advance
-Aline

At first you have not to be S-OFF in order to flash a rom.
Your rom will get installed just fine.You just need to flash the kernel of your rom manually through fastboot using the command fastboot flash boot boot.img.
What exactly do you mean by telling "so i flashed it back"?
Did you relocked your bootloader with fastboot oem lock and you flashed an RUU?
You said you are just rooted.If my theory was right you probably unlocked your bootloader again by flashing the unlock.bin and a cwm recovery and then you had to use a (Superuser , SuperSU zip).
The first time you unlocked your device was you using the same computer with windows 8?
If yes this is a problem.Check your device manager for unrecognised devices.Can you see the device?
Check this out.You can also check this.
(You can try with win7 or a linux destribution instead.)
Are you still able to boot into bootloader (hboot) using (Power)+(Vol-) Buttons?
If you have enabled usb-debugging and a working adb shell despite you are in a bootloop you can try:
Code:
adb shell
su ------>(If you don't see # instead of $)
reboot oem-78 -------> To get in RUU mode
or
reboot bootloader -------->(To reboot into hboot)
* reboot recovery could bring you to recovery *
If you can get into hboot or RUU mode give the command fastboot getvar all and copy-paste what it prints.

I know it was possible to flash with S-on,
thats what i tried and it failed (manually flashed the boot.img resulted in a bootloop)
so i flashed back to the "stock" rom.
resulting in a "normal" rooted device
since i've replaced my recovery and got root access
it never has been oem locked again.(still isnt)
i cant get into my bootloader/ruu mode. nor start up.
when i plug it into my computer (windows 8) it makes the sound as it does when you connect a device.
but in device manager it shows nothing, not even a yellow ! as it normally would if it can recognize a device.

aline1996 said:
I know it was possible to flash with S-on,
thats what i tried and it failed (manually flashed the boot.img resulted in a bootloop)
so i flashed back to the "stock" rom.
resulting in a "normal" rooted device
since i've replaced my recovery and got root access
it never has been oem locked again.(still isnt)
i cant get into my bootloader/ruu mode. nor start up.
when i plug it into my computer (windows 8) it makes the sound as it does when you connect a device.
but in device manager it shows nothing, not even a yellow ! as it normally would if it can recognize a device.
Click to expand...
Click to collapse
As you have not access to bootloader but your device is still seems to get connected i think you can only try HTC Unbricking Project.If the brickdetect.sh is not working you can try a different linux destribution.

Gatosbil said:
As you have not access to bootloader but your device is still seems to get connected i think you can only try HTC Unbricking Project.If the brickdetect.sh is not working you can try a different linux destribution.
Click to expand...
Click to collapse
Well, i just wonder which package i need, tried the links at the bottom of the post but those are no longer valid :/

aline1996 said:
Well, i just wonder which package i need, tried the links at the bottom of the post but those are no longer valid :/
Click to expand...
Click to collapse
Oups!I downloaded those packages some days before and I didn't see the links are broken now.
You can download them from the attachments here.
For Sensation and Sensation 4G

Gatosbil said:
Oups!I downloaded those packages some days before and I didn't see the links are broken now.
You can download them from the attachments here.
For Sensation and Sensation 4G
Click to expand...
Click to collapse
Well im afraid my phone is offically dead
this is what i get when i use ./brickdetect
[email protected]:/media/sdc$ ./brickdetect.sh
Searching for bricked device...
Device can't be detected. Check connections
[email protected]:/media/sdc$
please tell me i did something wrong xD
edit:
after some digging in knoppix i did find this:
http://imgur.com/DR7T4QK

Arrrrg did I brick the thing, stuck on HTC screen after using TWRP.

So I got somebody to help me out with the $25 on Sunshine, S-off, unlocked, rooted. I go to Google Play and get TWRP and go to "TWRP install" select my phone type, the newest build and I install it, says it installed fine and asked to boot into recovery mode which just takes me to a triangle and an exclamation point. I vol -/+ power to restart and it sticks me on the "HTC" boot up screen, I vol + and power with a quick transition to vol - to try and do a factory reset and start over again and it won't even allow me to do that. Now what? Did I brick it? Does anybody have a link that'll get me out of this mess and get a custom rom flashed on here?
Thank you!

I'm still at it trying to get an older version of TWRP on it via ADB which I installed on my Mac but I can't get the Mac to recognize the M8 so I am messing something up along the way. Does anybody know how to get this done?

I always do my best to document my progress so that it's solved for the next person that has an issue. I'm still stuck and have tried installing the SDK tools on both Mac and Windows and I can't get ADB to pick up the device in fastboot mode on either. I'm typing this on a Linux machine, I guess I could try it from here for fun but I'm guessing there's some other issue going on. I'm just trying to figure out how to get TWRP flashed on at this point so I can get out of my soft brick issue.

Tucson85743 said:
I always do my best to document my progress so that it's solved for the next person that has an issue. I'm still stuck and have tried installing the SDK tools on both Mac and Windows and I can't get ADB to pick up the device in fastboot mode on either. I'm typing this on a Linux machine, I guess I could try it from here for fun but I'm guessing there's some other issue going on. I'm just trying to figure out how to get TWRP flashed on at this point so I can get out of my soft brick issue.
Click to expand...
Click to collapse
While phone is in fastboot, you need to use fastboot commands, adb won't work. Connect phone to pc while in fastboot mode then try typing in "fastboot devices" and hit enter. If it shows you device S/N then you are good to go. To flash recovery you normally use "fastboot flash recovery recovery.img" assuming you renamed the twrp file to recovery.img
If you cant get that to work, you might try looking for the RUU file for your device to reset your device back to completely stock firmware and start over.
Hope this helps!
Sent from my A0001 using XDA Free mobile app

Klown80 said:
While phone is in fastboot, you need to use fastboot commands, adb won't work. Connect phone to pc while in fastboot mode then try typing in "fastboot devices" and hit enter. If it shows you device S/N then you are good to go. To flash recovery you normally use "fastboot flash recovery recovery.img" assuming you renamed the twrp file to recovery.img
If you cant get that to work, you might try looking for the RUU file for your device to reset your device back to completely stock firmware and start over.
Hope this helps!
Sent from my A0001 using XDA Free mobile app
Click to expand...
Click to collapse
That was a HUGE help actually and this is way easier on my Linux box. It's communicating in fastboot but won't boot into TWRP when I go to recovery yet. I'm trying to fastboot a custom rom to it now to see if that works but am having some issues thus far but will keep at it.
****Edit So I think it was the version of TWRP I was using that was the issue this entire time. I tried 2.8.7 which caused the issues, then to flash 2.8.3 and 2.7.0.1 to try and get something to recover from with no luck and finially I used fastboot on Linux to get 2.8.0.0 on it and it's going into recovery find from that.
****Edit 2.0 I have TWRP working but can't wipe or install and keep getting an error "twrp unable to mount /system" so I need to address that somehow, how sure what the issue is but I'm worn out on it so any help or ROM suggestions to use from here would be amazing!
****Edit 3.0 After retrying with 2.8.7 and it not working at all I tried with 2.8.0.1 and had the same issue so I went up to 2.8.0.2 and that fixed it now I just need to find the right rom to download and flash.
****Edit 4.0 Okay I am all set and figured out the issues and have SlimKat running on it now. Thanks for that little nudge in the right direction!

I somehow broke TWRP

I haven't really touched this tablet in a while, but i wanted to start using it again. I was running BlissPop. It was slow, and kept giving me an error when it was trying to update, so I decided to try a different ROM. So I downloaded the lineageOS ROM and tried to flash it.
However, TWRP kept giving me an error when I tried to flash the ROM. I don't remember exactly what the error was.
So, I thought that I needed to update TWRP. I tried through the "Official TWRP" app, but after doing so I was unable to boot into recovery mode at all. I could still get to the bootloader, but when I tried to select recovery mode it would give me an error and dump me back out to the bootloader menu.
I tried installing twrp through "TWRP Manager" app, but it just says "something went wrong"
I tried doing this using ADB. I connected the tablet, enabled USB debugging. If i do the ">adb devices" command, I can see the tablet. Then I did >adb reboot bootloader - which works, it reboots the device into the bootloader. But then I try and flash recovery and nothing happens, it just says <waiting for device>. And if I do > fastboot devices it doesn't list any devices.
If I reboot to the bootloader and select "Recovery Mode' i just get the nvidia boot logo and it stays there forever.
I don't know what else to try at this point.
I think I could get this to work if I could just get fastboot to recognize my device, but I'm not sure what's preventing that from happening.

mattlokk said:
I haven't really touched this tablet in a while, but i wanted to start using it again. I was running BlissPop. It was slow, and kept giving me an error when it was trying to update, so I decided to try a different ROM. So I downloaded the lineageOS ROM and tried to flash it.
However, TWRP kept giving me an error when I tried to flash the ROM. I don't remember exactly what the error was.
So, I thought that I needed to update TWRP. I tried through the "Official TWRP" app, but after doing so I was unable to boot into recovery mode at all. I could still get to the bootloader, but when I tried to select recovery mode it would give me an error and dump me back out to the bootloader menu.
I tried installing twrp through "TWRP Manager" app, but it just says "something went wrong"
I tried doing this using ADB. I connected the tablet, enabled USB debugging. If i do the ">adb devices" command, I can see the tablet. Then I did >adb reboot bootloader - which works, it reboots the device into the bootloader. But then I try and flash recovery and nothing happens, it just says <waiting for device>. And if I do > fastboot devices it doesn't list any devices.
If I reboot to the bootloader and select "Recovery Mode' i just get the nvidia boot logo and it stays there forever.
I don't know what else to try at this point.
I think I could get this to work if I could just get fastboot to recognize my device, but I'm not sure what's preventing that from happening.
Click to expand...
Click to collapse
Did you set:
Allow oem unlock in dev opt.
Fastboot protocol into BL?
Twrp app & manager need root to work.

Just flash the latest stock ROM first, lineageos requires having latest firmware.
I wrote a little guide not long ago about that (obviously, you can skip the F2FS steps if you don't need F2FS and just flash ROM after flashing latest TWRP)
Link

thanks for the help, i'll try and work through this soon.

fpozar said:
Just flash the latest stock ROM first, lineageos requires having latest firmware.
I wrote a little guide not long ago about that (obviously, you can skip the F2FS steps if you don't need F2FS and just flash ROM after flashing latest TWRP)
Link
Click to expand...
Click to collapse
I had seen your thread, and was intending on following it. nice post. 2 quick questions though
1) this is a shield tablet that was supposed to be remotely bricked by nvidia after the warranty claim. Will that happen if I flash the official recovery ROM?
2) how would I even flash that rom if I can't get recovery mode to work in trwp?
I think the root problem that I'm having is that I can't seem to connect to the device via fastboot (i'm sure i used the wrong terminology somehow)
edit: well I downloaded the USB driver for the shield tablet from nvidia, and i was able to install that (rather than the google usb driver). Fastboot finally recognized my device after that. I'm trying to flash the recovery now, but it doesn't seem to be doing anything, just been stuck on this screen for a while now: https://i.imgur.com/BUwj3Hx.png guess I'll continue to wait a while.
edit 2: well, finally got TWRP to flash over fastboot (https://i.imgur.com/tV1DqDv.png) however I still can't enter recovery mode. I just get the nvidia boot logo and then nothing happens. TWRP manager still says i don't have it installed either.
i'm about ready to give up on this... i've spent like 6 hours on this crap already and I feel like I keep getting further away from it.

mattlokk said:
I had seen your thread, and was intending on following it. nice post. 2 quick questions though
1) this is a shield tablet that was supposed to be remotely bricked by nvidia after the warranty claim. Will that happen if I flash the official recovery ROM?
2) how would I even flash that rom if I can't get recovery mode to work in trwp?
I think the root problem that I'm having is that I can't seem to connect to the device via fastboot (i'm sure i used the wrong terminology somehow)
edit: well I downloaded the USB driver for the shield tablet from nvidia, and i was able to install that (rather than the google usb driver). Fastboot finally recognized my device after that. I'm trying to flash the recovery now, but it doesn't seem to be doing anything, just been stuck on this screen for a while now: https://i.imgur.com/BUwj3Hx.png guess I'll continue to wait a while.
edit 2: well, finally got TWRP to flash over fastboot (https://i.imgur.com/tV1DqDv.png) however I still can't enter recovery mode. I just get the nvidia boot logo and then nothing happens. TWRP manager still says i don't have it installed either.
i'm about ready to give up on this... i've spent like 6 hours on this crap already and I feel like I keep getting further away from it.
Click to expand...
Click to collapse
Okay so I'm guessing you have stock ROM.
To flash TWRP you have to enter fastboot mode (vol down + power I believe) and flash the twrp image with fastboot flash recovery twrp.img (rename the shield tablet twrp to just twrp.img and place it into your easy adb and fastboot folder)
And DON'T reboot into OS, rather use your volume buttons to navigate to "restart to recovery" or just use hardware keys again directly from TWRP (vol up + power).
Good luck

fpozar said:
And DON'T reboot into OS, rather use your volume buttons to navigate to "restart to recovery" or just use hardware keys again directly from TWRP (vol up + power).
Good luck
Click to expand...
Click to collapse
Agreed. This is probably what is happening (as described on the TWRP webpage here:
Note many devices will replace your custom recovery automatically during first boot. To prevent this, use Google to find the proper key combo to enter recovery. After typing fastboot reboot, hold the key combo and boot to TWRP. Once TWRP is booted, TWRP will patch the stock ROM to prevent the stock ROM from replacing TWRP. If you don't follow this step, you will have to repeat the install.
Alternately, immediately rooting (flash SuperSU or Magisk) right after flashing TWRP, will prevent TWRP from being replaced with stock recovery.
Although the inconsistent fastboot connection, and how much trouble you had flashing TWRP initially, is a bit worrisome. Try using a different cable (maybe the one you are using is not connecting well?) try another USB port on the computer, and don't use a USB hub (connect direct to the PC).

Well, like they say: persistence is key. I kept pushing and trying new things until eventually.... I bricked the device. No, not really, it's working great now on LineageOS.
Thanks again to everyone who helped me out :good:. I'm still not sure exactly what caused TWRP to stop working on my device, however following this guide helped me fix it: https://forum.xda-developers.com/shield-tablet/help/help-stuck-nvidia-boot-screen-t3076462
The "flash-all.bat" restored everything to stock (including the recovery mode) and after that I was able to flash the latest TWRP and install Lineage.