Hardware Teardown - Coby Kyros 7015/7016

Coby Kyros 7015 and 7016 have same hardware, main difference is Android version.

A friend of mine has consulted me regarding one of his children's two Coby Kyros 7016 MID which don't detect previously installled games. I have installed ClockworkMod Recovery and upgraded these tablet's rom to CyanogenMod 7 before in the past. Upon further investigation, I found out that the internal memory and sd card has not been mounted.  Playing around with /system files including volds.fstab and some other various mounting methods using terminal emulator (in the device) and adb (using PC and Mac), I was out of luck. I finally decided that the problem most probably is hardware-related.

Opening up the tablet required moderate effort. No screws were used and the back cover was only held tightly by clips all around. Using my trusty old credit card, I pried it open, starting from the edge where the ports are located. Inching my way until all edges are free from the clips.

Once the back cover is free, I carefully removed 4 screws holding the logic board to the front case below (red circles). Unhook the digitizer from the clip (yellow rectangle) and resistive lcd screen flex cable (blue rectangle).

Carefully free the ports from the case then gently fold the logic board over the battery.

THE CULPRIT

Cheap devices came from cheap manufacturing process obviously. Wave soldering done properly should not have resulted in this. Because of mechanical stresses, the sd card slot module has come off the solder points in the logic board! 

Using my smd rework station, I tried to solder back the pins to the logic board using ample amount of flux. Reassembled. Unfortunately, it still does not work! So I had to repeat the process but this time soldering using a fine tip iron, thin solder, magnifying glass and lots of light. Pin by pin, I soldered manually including the 4 tabs at the edges of the sd card slot module for better support from mechanical stresses in the future. 

Reassemble by reversing the process. Finish!

EXTRAS
Since I have accessed the internals of the Coby Kyros 7016, I indulged myself of taking pictures while I'm at it.

The Battery
2450mAh 3.7v

Multi Core Module

• The Processor: Telechips TCC8902 (500-800Mhz) RISC type 32-bit 65nm
• GPU: ARM Mali200 
• RAM: Hynix 256MB
• Memory: 2x Samsung 2Gb
• Atheros Wifi Chip
• free USB port (1) 

Wifi Antenna (gold plate) attached to logic board by gray wire

Rooting the Proper Way

Running scripts should provide the easiest way to root.  Unfortunately, most of the time it only offers temporary root.  Rebooting the device reverts back to unrooted state.  Sometimes, elbow grease is needed to get the job done properly.

MANUAL ROOTING
1. Install Superuser from Market.  Go to its Prefs and update su binaries.  Reboot.
2. Install Busybox by Jrummy from Market.  Run it, then allow and remember as superuser (su).
3. Install busybox ver. 1.19.3 to /system/xbin first.
4. Then install busybox ver. 1.19.3 to /system/bin.  Reboot.
5. Try installing the latest Titanium Backup from Market to test.

Flash Firmware via Livesuit

Here is the instruction from Futeko.com that I used.  (Download link at the bottom)

• Please note that the update wipes the tablet's internal storage and starts from scratch. So you will lose all downloaded Apps and data. If neccesary back up your data first!
• Firmware must be flashed using a Windows application called Livesuit. Download it from the link to the left.
• Once downloaded, and before attaching your tablet to your PC, run the file 'LiveSuitPack_v1.07.exe' from within the Livesuit folder. This should install a new device on your system (VID_1f3a_PID_efe8). This device may show with an exclamation mark in Windows Device Manager, this doesn't matter and can be ignored.
• Now download the firmware image you want to install. Firmwares are linked to in the downloads section to the left. After decompressing the archive you will end up with a .img file (e.g. 'sun4i_crane_t01a_0.8.1_20120224.img'). This is the firmware/ROM image that you are going to flash (or copy) to the tablet.
• Without attaching your tablet to your PC run 'LiveSuit.exe' from within the Livesuit folder. You should get an application with 6 icons.
• You will be asked if you want to be guided through the process, select no.
• Click on the leftmost icon (a cube), browse to your downloaded firmware image, and select it.
• Turn the tablet completely off. The tablet should be off throughout the update process.
• Now attach your tablet to your PC by USB cable whilst holding down the volume+ button on the top. Straight after attaching the cable, and whilst still holding down the volume+ button, start pressing the tablet power button repeatedly (approx 1 press per second for 10 seconds is enough). This procedure puts the tablet into update mode.
• After a few seconds a window will pop up on your PC asking if you want to perform a forced firmware update. You can release volume+ at this point. Select yes. You will be asked if you're sure. Select yes.
• The update will start and will take take approx 3 minutes to complete. You will see a % complete progress bar during the process and will get a dialog saying OK when it's done.
• Turn your tablet on and you will have the new firmware.

DOWNLOAD LINKS (I uploaded the file in Mediafire for easier and faster download)
                                     Livesuit 1.07

Here's the link of Eken T01a latest (June 2012) firmware I uploaded.
                                         Part 1
                                         Part 2
                                         Part 3

Eken T01a Firmware Upgrade

Ice Cream Sandwich Firmware update is up on Eken's site.  This fixes some bugs, added battery stats in settings and more importantly, the gyro for some games like Temple Run. Here's the link.

How to upgrade firmware on your Eken Tablet PC:

1. Download the firmware files above.
2. Unzip the rar file to a folder.
3. Open the zipped folder and copy all its contents to an empty micro sd card.
4. Turn off device and insert micro sd card.
5. The upgrade process will start automatically when you turn on your device.
6. Upgrade finished! Remove micro sd card.
7. The device should reboot automatically again. If not, manually reboot it.

Here's the link of Eken T01a latest (June 2012) firmware I uploaded for faster download.

       Part 1
       Part 2
       Part 3

Modifying Build.prop in PC

Image courtesy of Androidsis.com

Modifying build.prop using your device is handy as it won't need connection to a computer and typing complicated shell scripts.  Unfortunately, bad luck happens and some things just do get wrong sometimes.  You will need to use the pc to revert back to your build.prop backup.

TO MODIFY BUILD.PROP VIA ADB (Android Debug Bridge)
     1. On your device, go to Settings-Applications-Development, turn USB debugging on.
     2. Connect device to pc.  Do not mount storage card.
     3. Download the ADB files if you haven't already got them.
     4. Extract the 3 files to the root of your Windows drive (C:\).
     5. Go to "Run" or "Command Prompt" and type cmd, Enter key.
     6. Type CD.. repeatedly until you just see "C:\"
     7. Type "ADB" and Enter key.
     8. To copy build.prop to root directory of Windows, type

                                ADB pull /system/build.prop c:\

     9. Now open build.prop saved in C:\ with Notepad. Edit as you wish. Save.
     10. To put modified file back to device, type

                                ADB remount
                                ADB push c:\build.prop /system/
                                ADB reboot 

     11. Unhook usb cable. Done!

TO REVERT BACK BUILD.PROP BACKUP

     1. On your device, go to Settings-Applications-Development, turn USB debugging on.
     2. Connect device to pc.  Do not mount storage card.
     3. Download the ADB files if you haven't already got them.
     4. Extract the 3 files to the root of your Windows drive (C:\).
     5. Go to "Run" or "Command Prompt" and type cmd, Enter key.
     6. Type CD.. repeatedly until you just see "C:\"
     7. Type "ADB" and Enter key.
     8. To copy build.prop.bak to root directory of Windows, type

                                ADB pull /system/build.prop c:\
                                ADB pull /system/build.prop.bak c:\

     9. Delete build.prop. Rename build.prop.bak to build.prop.
     10. To put back modified file back to device, type

                                ADB remount
                                ADB push c:\build.prop /system/
                                ADB reboot 
     11. Unhook usb cable. Done!

Internal Memory and External SD Card Swap

After installing a couple of games and apps, Android tells you that you are out of storage space.  So you head on to ebay and buy the largest sd card your credit card can buy.  You slap in your brand new sd card and head on to install more apps, only to find out you still have no storage space left despite moving apps to sd card.

WHAT HAPPENED?
Android tablets in general, has a different directory structure compared to Android phones.  Mine has 504MB for apps (in system), 2.67Gb internal storage (sdcard), and mounts external sd cards as (extsd).  By default, external sd cards (extsd) are only used for media storage.  Unfortunately, apps only recognizes sdcard, so your media files will still need to be transferred to internal storage for it to be played. What's the point?

THIS HACK
This hack will swap the position of the internal sd card to the external one you bought earlier.

1. Using any file manager (Root Explorer), navigate to /etc.
2. Copy vold.fstab to root of your extsd and transfer to pc.
3. Using a text editor (Notepad), edit the following lines:
 
       dev_mount sdcard /mnt/sdcard auto /devices/virtual/block/nand1
       dev_mount extsd /mnt/extsd auto /devices/platform/sunxi-mmc.1/mm_host /devices/platform/sw_hcd_host0 /devices/platform/sw-ohci.1 /devices/plaform/sw-ohci.2
                                                      TO
             dev_mount extsd /mnt/sdcard auto /devices/virtual/block/nand1
        dev_mount sdcard /mnt/extsd auto /devices/platform/sunxi-mmc.1/mm_host /devices/platform/sw_hcd_host0 /devices/platform/sw-ohci.1 /devices/plaform/sw-ohci.2

4. Save.
5. Copy edited vold.fstab file back to /etc.
6. Reboot. Done!

MAKING LIFE EASIER
Sergey_F1 has made the process easier for novice users by creating a script for Allwinner Tablets in this link.

 1. Download the script (updated for all Allwinner devices)
 2. Unpack .zip file
 3. Connect tablet to pc in usb debugging mode, do not mount sd card!
 4. If Windows asks for drivers, install this in 32-bit or 64-bit
 5. Run SDvue.exe, Enter.
 6. Tablet will reboot.  Remove cable.
 7. Done!

Increase Wifi TxPower

Txpower is a property key in build.prop that controls the transmit power of the wifi module via its own driver.  You can manually modify its key from 0-100. Reboot.

Set it too low, wifi signal suffers.  Set it too high, and the battery life decreases or the wifi module may overheat and decrease in performance instead.  Personally I set mine between 70-80.  Other forums recommend 15.  Alternatively, you can use Wifi TXpower from the Google Playstore for ease of use.

Natively, some devices do not support "iwconfig".  You can download it here and copy it to /system/bin. Please leave a comment below if you need help with this tweak.

Build.Prop Tweaks

In the past, we have showed you how to modify the build.prop file for your personal customizations.  Below is a list of build.prop tweaks and a description what it does.  You can add a property name and its key
manually if it is not listed in your build.prop.

Faster scrolling:     ro.max.fling_velocity=12000 
                             ro.min.fling_velocity=8000

Power Saving:         pm.sleep_mode=1 
                             ro.ril.disable.power.collapse=1 
                             windowsmgr.max_events_per_sec=60 
                             wifi.supplicant_scan_interval=180  (less than 90 if you want faster reconnect to wifi after turning on, but may consume more battery life)

Increase media streaming performance:

                             media.stagefright.enable-player=true 
                             media.stagefright.enable-meta=true 
                             media.stagefright.enable-scan=false
                             media.stagefright.enable-http=true
                             net.tcp.buffersize.default=4096,87380,256960,4096, 16384,256960

                             net.tcp.buffersize.wifi=4096,87380,256960,4096,163 84,256960

Faster boot time:   debug.sf.nobootanimation=1   (disables boot animation)  

Spoof you device to show more apps/games in the Google Playstore by editing your build.prop!  What better way to do this than by installing Allwinner Mod from the Google Playstore?

Build.prop Editor

Android is a very customizable platform where the user is able to manipulate almost every aspect of the device on hand, to a point where it becomes more useful and more so, even playful.

Almost everyone who has tweaked an Android device probably knows what build.prop is and what it does.  To everyone else who don't, build.prop is a file located in the directory /system.  This file is the device's "ID card".  It tells an application (including the Android operating system) what your device specification is, and in turn, will provide specific function or interface.  It is loaded on boot.

Since this is a system file that we will be revising, the device will need to be rooted.  Most china tablets come pre-rooted from factory so it should not be a problem.  Sometimes you just need to install "Superuser" and "Busybox" from the Google Playstore so it becomes easier to use without adb and scripting in the computer.

Make sure /system directory is mounted as R/W (read/write).  Using any file explorer in your device, navigate to /system and look for the file build.prop.  Tap and hold on the build.prop file, edit in text editor, and type in and change the values.

Let's have one example for the Eken T01a:

Change the property name ro.sf.lcd_density to property key 112.  Reboot.

This is the lcd density I find best for me.  It displays 8 x 5 icons in the app drawer.  And shows me more content during web browsing or ebook/document reading.

MAKING THINGS EASIER
To automate the process, after all we are in the new tech age, you can use a build.prop editor app.  There are a couple of these on the Google Playstore and the best of it all...it comes for free.  I use build.prop Editor myself.

External Wifi

Cheap chinese tablets come with cheap components obviously to keep production costs down.  The wifi module used is no exception.  Signal range is moderate to low that just moving to the next room, connection is dropped.  Hence this mod.

I have opened the tablet in the past to reveal its components to address several issues.  I tried soldering magnet wires as antenna to the module in full, half, and 1/4 of the wifi wavelength.  While it increased the signal to around -10dBm (highest I got), the connection is still not reliable as I still encounter browser  and download timeouts.  In the future, I will solder-in a laptop antenna in hope that the wifi connection will be more robust.  Or transplant a new wifi module with built-in bluetooth to get things going!

I have also played around with txpower in the build.prop as the wifi module gets hot after a while of internet activity.  I assumed connection timeouts were caused by the module overheating.  I have set it at 80 presently and gives me a good compromise on heat, signal strength and battery life.  Iwconfig is not installed stock so I will show you that in another day.

For the meantime, I am using an external usb wifi adapter pictured below.  I chose this because it is tiny and does not protrude much on the case.  It is working wonderfully on the tablet.  It shows a faint blue light showing it is turned on and blinks when there is wifi activity.  

HOW TO USE

Turn off the wifi switch in Settings-Wifi.  Then insert the usb wifi adapter in the usb host port.  Then turn on.    Voila! It works! Don't you just love the usb host (USBOTG) functionality of this tablet?    

On stock Eken firmware, Realtek "drivers" are already incorporated so it should work out-of-the-box.  No need for insmod-ing linux drivers.  I have tried a Ralink based usb wifi adapter but unfortunately it shows no activity. 

WHY IT WORKS

The built-in wifi module is behind the metal backplate of the lcd screen, effectively blocking and interfering with the signal.  The proximity of the wifi module to the processor, ram, etc. chips and with no shielding exposes it to more electronic noise/interference.

Hardware Teardown - Part 3

Realtek USB Wifi chip. OXD Electronics, Co, Ltd, Shenzhen

Still thinking what USB chip to add as replacement. Perhaps a USB Wifi and Bluetooth combo?

Samsung SLC NAND Flash

Allwinner A10 Multicore Processor and Two 256Mbytes 128x16 (2048Mbits) DDR3 Ram chips

That's about it. Reverse the process to assemble back. Happy modding!

Hardware Teardown - Part 2

You will need specialized, precision-crafted, state-of-the-art equipments:

No. 0 Philips screwdriver
Old credit card you did not pay
and a wedge or a nail.  Your fingers! 

There are only 2 screws, encircled red in the picture.  Unscrew.  Careful not to lose the screws as they are very small.

Starting at the edge, use the credit card as a wedge and pry open.  Apply steady pressure until you hear a pop.  Inch your way until every side is cracked open.  Gently lay it side by side not too far from each other because the speaker wires are attached to the cover side.








Mono speaker that crackles with RF activity (e.g. Wifi, Processor)

I shielded it with Aluminum tape





The battery. 2300mAH 3.7v PL426095P

I ordered an 8000mAH 3.7v due to arrive in two weeks for transplant.

Hardware Teardown - Part 1

Manufacturer:  Eken

Model: T01a

Firmware: Android Ice Cream Sandwich 4.0.3
                 Build: IML74K..20120328
                 

Image courtesy of b2conlineshop.com

The patient at hand is a cheap, generic, 7" Android china tablet with a lot of cheap(!) complaints. Before even buying the thing, I instantly knew it needed hackery of sorts.  Now on to the reconstructive surgery after the jump..