TF201 DIY screen replacement learnings

[whbowers]

I also cracked the screen on my TF201 through a relatively minor drop onto a carpeted floor. I debated fixing it myself, but since it is a company owned machine I went with a commercial repair shop. The local UBREAKIFIX store in King of Prussia, PA had been recommended from an unfortunate iPhone user.

I called the store and found out that mine would be the first TF201 they worked on. I'll spare everyone the details and fast forward to a month and two screen replacements later and it was still backwards! It took a call to their corporate headquarters to convince them to simply replace the entire tablet with a new one.

I'm not trashing UBREAKIFIX. However, the King of Prussia store was not professional or customer oriented. They're apparently fine for iPhones, but not ASUS tablets.

Bill Bowers

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[T_RJ]

What version android?

[sawa]

Ok, as i promised here are instructions for repair TF201 with inverted digitizer.

You will need nvflash, Android SDK to install nvflash and modified kernel (for WW-9.4.2.28 and for WW-10.4.2.15)

1. First of all you need to install nvflash as described here http://androidroot.mobi/t3_nvflash/. And make backups!!!
2. Reboot tablet in APX mode (turn tablet off, press volume up and turn tablet on)
3. Run

wheelie --blob blob.bin

to load nvflash mode
4. Make backup of your original kernel

nvflash --resume --read 6 boot.img

5. Load modified kernel

nvflash --resume --download 6 ./newboot.img

6. Boot device

nvflash --resume --go

That's all.

If your device firmware differs from WW-9.4.2.28 or WW-10.4.2.15 you need to build you own kernel. I will describe it for a linux.

1. Download Android NDK
2. Download you original kernel sources from Asus site.
3. Unpack sources, find file

drivers/input/touchscreen/atmel_maxtouch.c

4. Find lines:

if (mxt->max_y_val < 1024)
ypos >>= 2;

stored_x[touch_number] = xpos;
stored_y[touch_number] = ypos;
fingerInfo[touch_number].x=xpos;
fingerInfo[touch_number].y=ypos;

replace them with

if (mxt->max_y_val < 1024)
ypos >>= 2;
xpos = mxt->max_x_val - xpos;
stored_x[touch_number] = xpos;
stored_y[touch_number] = ypos;
fingerInfo[touch_number].x=xpos;
fingerInfo[touch_number].y=ypos;

5. Connect your device to computer and turn it on. Download .config file from your device

adb pull /proc/config.gz ./

Ungzip config.gz to your kernel sources root folder and rename it to .config
6. now build your new kernel
in your kernel sources root folder run

make ARCH=arm CROSS_COMPILE=[PATH_TO_NDK]/toolchains/arm-linux-androideabi-4.6/prebuilt/linux-x86/bin/arm-linux-androideabi-

replace [PATH_TO_NDK] with your real path
7. If everything fine you can find file

arch/arm/boot/zImage

in you kernel sources
8. Install nvflash, backup, reboot to APX and dowload your kernel image

nvflash --resume --read 6 boot.img

9. Get BootTools and compile them https://github.com/AndroidRoot/BootTools
10. Unpack boot.img file with

bootunpack ./boot.img

11. Copy zImage to BootTools folder
12. Pack new kernel image

./mkbootimg --kernel ./zImage --ramdisk boot.img-ramdisk.cpio.gz -o ./newboot.img

13. Upload kernel image to device

nvflash --resume --download 6 ./newboot.img

14. Boot device

nvflash --resume --go

If you have troubles with your new kernel rollback to your original one:
1. Boot to APX, boot nvflash, run

nvflash --resume --download 6 ./boot.img

[cocomoe]

Hey Sawa! Very nice work!! My problem is that I'm on JB WW-10.4.2.15 and I did not enable NVFlash before I upgraded to JB so I have no chance on getting NVFlash activated because of the JB Bootloader.

I unlocked the device and now I am able to install another (JB) rom and I would change the kernel as you described but I'm on windows and I have no Idea of compiling and stuff on linux.
Hope it's not to much to ask for but could you post the complete JB 4.1.1 rom with the fixed Kernel inside so I can just flash it?

Would help me a lot! Thanks

[deconzme]

great work. my friend and i tried your fix today.. all day today. it seems we got everything right, except the kernal would not compile with the rom. so we are in the same spot as Cocomoe! if you could make a ROM all built in to fix this, that would be amazing! I am rooted, and unlocked on a jelly bean rom. fyi.

thank you so much for your work!

[sawa]

Here is kernel for WW-10.4.2.15 - http://darksawa.ru/files/4.1.1/newboot.img, may be you didn't noticed it in my post. I'll try to build complete firmware later for those who have already flashed 4.1.1, but don't know when - have a lot of work to do.

[deconzme]

thank you for for saying yes to a complete package. it doesnt need to be anything special.. litterally stock with the fixed x axis kernal would be awesome!

Here is kernel for WW-10.4.2.15 - http://darksawa.ru/files/4.1.1/newboot.img, may be you didn't noticed it in my post. I'll try to build complete firmware later for those who have already flashed 4.1.1, but don't know when - have a lot of work to do.

[deconzme]

i dcant, dont have nv flash, same as the other guy, .we didn't start it before the upgrade.

[deconzme]

we tried packing your kernal with another rom.. no luck. i am not sure whats wrong. i hope you can get some time to do it soon! thanks again.

[cocomoe]

Here is kernel for WW-10.4.2.15 - http://darksawa.ru/files/4.1.1/newboot.img, may be you didn't noticed it in my post. I'll try to build complete firmware later for those who have already flashed 4.1.1, but don't know when - have a lot of work to do.

I also tried it without success.. What I did:

- Download Stock Rom WW-10.4.2.15 from Asus Website
- Unpack zip and blobunpack the blob-file
- Download your custom Kernel and renamed it to blob.LNX, then replace the original blob.LNX
- Blobpack the 5 partitions (EBT, PT, SOS, APP, LNX) to blob file
- Replace the original blob of the downladed ROM with the fresh created blob file
- Flash via TWRP

Axis still inverted.

EDIT: I noticed that after the flash the TWRP is still there so it seems that the flashing procedure was not successful. If it was there would be the stock recovery again.