[Nexus 7 Q&A, Help & Troubleshooting] bokisis:
PROBLEM SOLVED! I used another pc, my usb ports were the problem! I recently got my Nexus 7 (2012), wi-fi only , I unlocked it's bootloader, installer TWRP recovery, and rooted it. For all these operations i used the N7 toolkit , because back then, I was a noob. The rooted tablet (4.2.2) worked Perfectly! But, after about 3 months, it's "volume down" button stopped working. I rebooted it, but it went in bootloader, instead of normal system. So I just select "Start" and it was in Safe Mode! OK, my "volume down" didn't work in Safe Mode (and bootloader mode) neither! And every time I reboot it, it goes to bootloader! I thought that it was a software problem (:confused:) , so I began flashing a new ROM. I didn't want to use the toolkit because everyone says that it's bad . I downloaded AndroidSDK, I re-downloaded the ADB and Fastboot drivers, and I downloaded the newer version of the bootloader (4.23, .img) . Tablet was already in bootloader and I connected it to the PC. In platform-tools folder I ran the "fastboot devices" command, and It was able to see it . So I copied the bootloader img to the same folder, and I ran "fastboot flash bootloader bootloader-grouper-4.23.img" . Then I rebooted it into bootloader again. IT WORKED! But, it didn't solve the "volume down" problem. My rooted 4.2.2 and TWRP were still on the system. Everytime I power off the tablet, and then hold the "Power" button, it goes into bootloader. It was that button issue causing that. Then I decided to take it to the service (same place where I bought iw the unloct) , but I couldn't because if they saked bootloader, non-stock recovery and the root, the wouldn't accept the warranty . I decided to download the latest 4.3 stock android, and stock recovery, flash them, and lock the bootloader. I downloaded 4.3 stock from google's official site, (nakasi-jwr66y) and I used the flash-all.bat command that came with it.

.bat command looks like this:

PATH=%PATH%;"%SYSTEMROOT%\System32"

fastboot oem unlock

fastboot erase boot

fastboot erase cache

fastboot erase recovery

fastboot erase system

fastboot erase userdata

fastboot flash bootloader bootloader-grouper-4.23.img

fastboot reboot-bootloader

ping -n 10 127.0.0.1 >nul

fastboot -w update image-nakasi-jwr66y.zip

echo Press any key to exit...

pause >nul

exit

I ran it. It successfully did the oem unlock (it was already unlocked) , all the erase commands, and flash bootloader command. But it was stuck on

"fastboot -w update image-nakasi-jwr66y.zip" . It stays steady for about 30secs , and than it says

"sending 'system' (x-kb)"

After some time it just says Data transfer failure(too manly links) ...

I tried the same process billion more times, but same error :/

I tried

-Re-downloading and installing the drivers

-Changing the usb ports, and microUSB cables,

-Restarting the pc (of course)

-Re-downloading the nakasi-jwr66y

-Downloading the twrp recovery (it successfully flashes it)

-Re-downloading the whole SDK

But it DOESN'T WORK? What should I do? Is the volume-down issue hardware or software ?

Sorry for my bad English :////////

P.S. What is the difference between "fastboot flashall" and "fastboot update" ?