[Verizon Galaxy Note 3 Q&A, Help & Troubleshooting] Frank Westlake:
Subject: (SOLVED) MTP is failing to work after a hack attempting to enable USB mass storage connections.

ABBREVIATIONS USED HEREIN

"NOTE3":

- Verizon Galaxy Note 3

- SM-N900V (JSS15J.N900VVRUBMI9)

- Android 4.3

- Successful Root de la Vega <http://xdaforums.com/showthread.php?t=2481590> (thank you very much)

"NOTE0":

- AT&T Galaxy Note

- SAMSUNG-SGH-I717

- Successful root The Unofficial (by Flappjaxx and The Collective) (thank you very much)

- Android 4.0.3 after the root (I forgot what it was before; 3.0?)

"PC":

- Windows 8

- Using USB 3.0 port with USB 3.0 cable to NOTE3

SYNOPSIS

USB mass storage (block transfer mode) works on NOTE0 but not on NOTE3. I've read that this removal of USB mass storage is a new feature of Android 4 but that it may still work for external SD cards. It does NOT work on my Note 3, neither internal nor external SD, but it does work for both internal and external SDs on NOTE0. It seemed to me that perhaps MtpApplication.apk was the culprit, so I set about copying that application from NOTE0 to NOTE3.

CREATING THE FAILURE

- Ran 'adb backup ...' from PC.

- Copied MtpApplication.apk from NOTE0 to NOTE3.

- Mounted /System RW.

- Moved original "/System/app/MtpApplication.apk" to a safe location.

- Deleted "/System/app/MtpApplication.odex". I figured the new file would be dexified when first run.

- Copied NOTE0's MtpApplication.apk to NOTE3 "/System/app/MtpApplication.apk".

- Set -rw-r--r-- root root on MtpApplication.apk.

- Mounted /System RO.

- Rebooted.

- Got "Android is updating" notice.

- Connect to PC.

- + The normal Installer CD drive appeared in Windows Explorer for several seconds.

- + The device "N900V" did not appear as it always has in the past. There are no references to NOTE3 in Windows Explorer.

- + Reinstalled Samsung device drivers on PC and rebooted PC.

- + Rebooted NOTE3.

- + No change. The MTP application has the three checkboxes for MTP, PTP, and USB 3.0, and the check can be moved to each, but there is no apparent communication between NOTE3 and Windows Explorer. The notification tray does show the normal "Click here to change USB connection mode" or whatever it normally says. The Installer does run as before but it is not now followed by the Explorer link to "N900V". No apparent difference with debug mode enabled on NOTE3. Debug bridge (adb.exe) works fine.

ATTEMPTING THE REPAIR

- Mounted NOTE3 /System RW.

- Deleted "/System/app/MtpApplication.apk".

- At this point I noticed that the "MtpApplication.odex" file was NOT created.

- Copied original "MtpApplication.apk" back to "/System/apk/".

- Set "-rw-r--r-- root root" on "MtpApplication.apk".

- Mounted /System RO.

- Rebooted.

- I didn't notice if the "Android is updating" notice appeared. Maybe I wasn't looking.

- At this point all is the same as under "Connect to PC" above. Still a failure.

- Still no "MtpApplication.odex".

- Ran 'adb restore ...' from PC.

- Rebooted NOTE3.

- At this point all is the same as under "Connect to PC" above. Still a failure.

- Still no "MtpApplication.odex".

- Installed and ran OdexerTool (13-11-2013) by MatrixDJ96, 'sysapp' command. System applications, including MtpApplication.apk were odexed or reodexed. MtpApplication.odex now exists.

- Rebooted.

- "System is updating dialog with an incrementing counter.

- At this point all is the same as under "Connect to PC" above. Still a failure.

WINDOWS DEVICE MANAGER

Windows Device Mangler shows a device with errors:

. ---------------------------------------------

. Portable Devices

. SAMSUNG Mobile MTP Device

. ---------------------------------------------

Properties on "SAMSUNG Mobile MTP Device" shows:

. ---------------------------------------------

. This device cannot start. (Code 10)

.

. The process hosting the driver for this device has terminated.

. ---------------------------------------------

It remains that way after uninstalling and reinstalling the Samsung drivers and after a reboot while standing on my toes facing east with my right arm extended above my head and screaming "WOM-A-TOOMA WOM-A-TOOMA WOM-A-TOOMA".

This was NOT a solution:

. <http://xdaforums.com/showthread.php?t=1797344>.

Found the key "UpperFilters" and deleted that key, unplugged and plugged and still no MTP, PTP, or USB 3.0 connection.

None of the devices under "Universal Serial Bus Controllers" show an error.

REQUEST

- What did I do wrong?

- How do I undo that wrong?

- + Should I reapply the Root de la Vega? (Is that like a Spock Lock?)

- * How?

CONTINUING ATTEMPTS TO RECOVER

The next thing I hope to try is to unroot/restore, then root again with de la Vega, but the only unroot/restore instructions I can find are for retail locked devices.

- Found a stock ROM (http://xdaforums.com/showpost.php?p=46424497&postcount=1) and flashed it. Success on the flash but still no connection with Windows File Explorer.

- Flashed Root de la Vega again. Success.

SUCCESS!

Problem solved. Windows File Explorer again shows the .SM-N900V icon and it is usable. Flashing the stock system should have fixed it so perhaps I just didn't reboot enough or didn't wait long enough after the devices installer program finished.

I sure hope someone gives us USB mass storage so I can work directly with the device's file system because MTP and Explorer are not suitable for the work I wish to do. The debug bridge might work but it is nearly as cumbersome as MTP.

Frank

(Why can't I thank myself too?)