NVFlash for Dummies

OLD ARTICLE – Probably has errors

Installing ClockworkMod Touch & Stock Bootloader (1.2)

This guide was last updated 07/03/2012 by Ray 

Visit the NEW version of this guide if you want to install Jelly Bean (Android 4.1) on the GTab.

See my video instructions at the bottom of this article.

ClockworkMod Touch

NEW ClockworkMod Touch on gTab


The NVFlash tool (program) is the PRIMARY Starting Point for any major changes or software fixes to your GTab. If you are having ANY problems with your ViewSonic G-Tablet, this is THE guide to follow.

NVFlash – also called “APX mode” can be used for several essential functions. Regardless of your previous configuration, by using this guide, you should be able to perform the following operations:

  • Regain control of your GTab after it is “bricked” or otherwise unresponsive (stuck in a loop at the “3 birds” or some other screen, etc). See Note1 (below) if you continue to experience loops even after flashing with this version of NVFlash.
  • Increase the size of the system partition from 200Meg (stock) to 250Meg (this may explain some failed ROM flashes.)

Note1: Some of the newer ICS ROMs may be too large for your gTab even with a 250MB system partition (due to hardware issues on SOME gTabs). If you experience consistent boot loops when flashing a new ICS ROM to your gTab… TeamDRH has created another version of their great NVFlash package that will expand the system partition to 300MB. I do not recommend that you use it unless you are having problems. Still, click HERE to download that package. Use is exactly the same as the one we link below.

  • Return your GTab to a STOCK configuration with the 1.2-4349 Tap-n-Tap. (Recovery is NOT stock.)
  • Change the bootloader version on your GTab from (old) 1.1bl to (new) 1.2bl. Note here that – for current ICS ROMs – the bootloader version is NOT significant. You can use new ICS ROMs on either bl. BUT, the system partition must still be expanded. So, we recommend that you use our 250MB NVFlash which will also convert to 1.2bl.


  • This process will likely void your warranty.
  • Assume that EVERYTHING on the GTab will be erased or deleted. However, that is not entirely true. NVFlash cannot erase anything on the SDCard (see this post). STILL, anything can happen.
  • Any use of this guide (or anything on this website) is done SOLELY AT YOUR OWN RISK!

Neither Ray Waldo, this website, its owners, or operators take any responsibility for your actions related to the use of any article/guide on this site. You have been warned. 

DOWNLOAD OUR FILES. Even if you have used NVFlash before and already have it installed on your computer,  USE OUR VERSION instead:

DOWNLOAD: NVFlash with Stock ROM & CWMR Touch 5504  at the TeamDRH site here (or from us here.) This archive includes all the files that you will need (for both Windows & Linux) to install NVFlash and complete this guide. This guide will install both the Stock T-n-T operating system and the ClockWorkMod Recovery.


Using NVFlash:

Note: There are two modes of operation controlled by booting with the volume buttons:

  • You get into APX mode by pressing the power and MINUS button. The gTab will flash on then go black. When in that mode, the GTab appears dead but will respond to commands from the attached computer – using NVFlash. If you mistakenly get into APX mode, just hold the power button down for about 30 secs to power off and exit the APX mode.
  • You get into RECOVERY mode by pressing the power and PLUS button. When in that mode, the GTab has a menu of options to allow you to flash an update, reset to factory, etc. No USB connection or computer is needed to use Recovery. To get out of Recovery mode, always click on the “Reboot to SYSTEM.”


If you have already successfully used this (NEW) guide, then you can skip to the PROCESS section.

  1. Backup any data on the GTab that you wish to save and copy it to some external storage. These procedures potentially delete everything on your GTab.
  2. Charge the battery to at least 70%. It is also a good idea to leave the power cable connected during these operations.
  3. Power off the GTab & remove your external SDCard (if you have one in the device).
  4. Download the NVFlash file from above.
  5. Extract the archive and rename the extracted folder to nvflash.
  6. LINUX ONLY:  You must make the nvflash file executable – Open the nvflash folder; right-click on the nvflash file; Properties; Permissions tab; Tic the box to run the file as a program. Then - Skip to the “PROCESS” steps below.
  7. WINDOWS ONLY:  INSTALL the APX drivers located in the “Flash USB driver” folder.
  • On the GTab, hold the Volume minus (“-“) button AND the power button until the GTab comes on and then goes BLACK (this is the APX mode
  • CONNECT the USB cable between the GTab and your computer.
  • When the gTablet is detected by Windows, and you are prompted for drivers, point the wizard to the ‘Flash USB Driver’ folder (inside the new “nvflash” folder.
  • The driver install should complete normally and you will hear an audible connection sound.
  • Power off gTablet by pressing the Power button for ~5 seconds. 


Do not connect the USB cable to the GTab unless instructed to do so. Also, be sure to DISCONNECT the USB cable when the guide says to do so.

  1. WINDOWS ONLY: If you have not installed the APX/USB drivers, then go back to the “PREREQUISITES.” Step and complete this step first.
  2. On the GTab, hold the Volume minus (“-“) button AND the power button until the GTab comes on and then goes BLACK (this is the APX mode).
  3. Connect the USB cable between the GTab and your computer. (If you continued from the previous section, the cable may already be connected.)
  4. On your computer, open a COMMAND PROMPT (or terminal), CD (change directory) to the nvflash folder & run the NVFlash program: Windows users, run the nvflash_gtablet.bat —  Linux users, enter the command, “sudo sh ./nvflash_gtablet.sh (without the quotes. – note the space after the “sh” and before the “./nvflash” characters.)
  5. Wait. The NVFlash tool will only take about two minutes to complete. Do not proceed until it reports that it is finished.
  6. Turn the GTab off by holding the power button until the line of text at the top of the screen disappears.
  7. Remove the USB cable (You are finished with the computer. Everything else is on the gTab.)

Partition the SDCard

From user Steve T.: The new CWM uses different navigation buttons than the previous version and now even has soft buttons at the bottom of the screen which makes it much nicer. The big difference I saw was that the ‘home’ button on the right side is now the UP arrow and the ‘menu’ button below the ‘home’ button is now the DOWN arrow. I think the select button is now the ‘search’ (magnifying glass) button.

  1. On the GTab, start ClockWorkMod (CWM) RECOVERY: Hold the power and volume plus (“+”) buttons until the “recovery key detected” text appears at the top of the screen.
  2. Select “advanced” and press the Home/Enter button (arrow on the right side of the screen).
  3. Select “Partition Internal SD Card” and press Home.
  4. Select “4096M” and press Home – then select “0M” and press Home again. The GTab will report that it is “Partitioning Internal SD Card.” Do not touch the device until it reports “Done!” at the bottom of the screen.
  5. Repeat steps 3 & 4 but select “2048M” & “0M” (rather than 4096M & 0M).
  6. Select “+++Go Back+++” and press Home.
  7. Select “power off” and press Home.

Reboot into Stock

At this point, you will have the stock Tap-n-Tap operating system installed. It is a good idea to fully boot into T-N-T and assure that it is working before proceeding to flash a new ROM.

If you wish to flash a new custom operating system, here is our list of viable candidates: ROMs for the GTab

Video Instructions for NVFlash & Installing ICS


To determine if your device has the LARGER system partition…

(if you did this NVFlash, then it DOES.)

To check the size of your SYSTEM partition, open the Terminal Emulator app (free on Play Store), enter “df” (without quotes). The “Filesystem” area is at the top of the list (either turn the GTab to portrait mode or scroll up to view the top of the list). Check the line that ends “/system”.

My device (with 250meg system) reads:           /dev/block/mtdblock3 253696 216480 37216 85% /system

If your device shows something around 200000 instead of the 253696, then you probably have the smaller (200meg) system partition.


TELL US about your experience in the comments below.




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