[Nexus 7 (2013) General] sfhub:
By now folks realize there are different hardware variances for the touchscreen which is one reason why some people have issues and others do not.

Don't you hate it when you have a workable system, then an update comes along which fixes something, let's say GPS, but then your touchscreen goes down the tubes? Suddenly you have dead spots, dead bands, ghost/phantom touches, stuck touches, broken drags, etc. Touchscreen works ok when held or plugged in, but is unusable on a table?

Never fear, I've put together packages to handle 3 different variances of the touchscreen.

I was able to make the touchscreen usable again on 3 of 4 test units. The 4th was always bad even out of the box so it might be hopeless for that one.

I do NOT claim this will fix everyones' touchscreen and that isn't even the goal as it might be an impossible task.

The goal is to make 70-80% of the problem units usable (again), but even if only 50% become usable this is an improvement over the current situation.

On to the packages:

In the attached boot-ts.7z file you'll find 4 files:

boot-ts10-lock.img

boot-ts20-lock.img

boot-ts30-lock.img

boot-ts-unlock.img

the ts10, ts20, and ts30 packages handle 3 variances on the touchscreen

You basically try each one to see which works best for your particular touchscreen.

Once you find one (and hopefully you do) then it is locked in place so future updates won't mess up your touchscreen again. No more OTA performance anxiety.

Now let's say there is an update in the future which has touchscreen fixes you want to use, that is where the 4th package comes into play. Once you use the ts-unlock image, you will once again be using touchscreen updates from the manufacturer. If that update doesn't work out, you can go back and use the ts10/20/30 package that was working for you.

Ok, so how does all this work?

I tried to make the process as simple as possible (has been tested on JWR66N, JSS15J, and JSS15Q, will work on LTE and custom ROMs also):

Your bootloader must be UNLOCKED to use these packages. Unlocking your bootloader is covered in this post.

unpack the boot-ts.7z package using 7-zip

you'll be left with a boot-ts directory with the aforementioned files

connect your tablet by USB

make sure USB debugging is enabled

Settings->About tablet [tap "Build number" 7 times]

Settings->Developer options [check "USB debugging"]

you can find adb/fastboot drivers HERE

in a command prompt in the boot-ts directory type (commands in italics)

adb reboot bootloader

wait for the bootloader screen to come up

alternatively use Power+VolDown to get to the bootloader/fastboot screen

fastboot boot boot-ts10-lock.img

this is how you try out package ts10

the screen will hang for 18-24 seconds, this is NORMAL, do not touch

this does NOT flash over your existing kernel

wait until Android is COMPLETELY booted

Note: if you are on Android 4.4 the stock 4.3 kernel will not get past the BouncingBalls

wait 120 seconds for the boot to settle down

press/hold the Power button 10-15 seconds until the tablet reboots

proceed to next step

adb reboot

after booting to Android you MUST reboot at least once

IGNORE any instability up to this point, it is expected

if adb reboot does not work for some reason, use the power button to shutdown/reboot

once you are booted into Android the 2nd time, try out the touchscreen and see if it feels usable

if there is instability, give it one more reboot back into Android before judging

if things are not working acceptably

repeat step #3, with ts20, and ts30 if needed

hopefully between ts10, ts20, and ts30, you will have found a package that works for you

there is nothing else for you to do

you can reboot and use your normal ROMs, custom ROMs, stock kernels, custom kernels, etc.

your touchscreen package is locked in place and won't change unless you want it to

if you want to go back to the way it was before and/or you want a future touchscreen update from the manufacturer

repeat step #3 using boot-ts-unlock.img

upon first reboot you will have the touchscreen software from the installed ROM/kernel

Please post feedback with:

the version of software you are running

what was/is broken

whether any of the packages helped

Remember to click thanks if you find this useful.

That's it folks, hope this helps somebody.