Touch Out of Sync

[karl kearsley]

Hi guys/gals my names karl. I own a cheap AllWinner A23 9" tablet. its always done what I needed it too... and then.... I broke the digitizer. so, I replaced the screen with an exact replica ( I have made sure all connections are perfect.) and when I turned it on, the touch was out of sync. I touch the screen and it thinks I am touching a cm to the left. the scale changes tho, the more towards the bottom right of the screen I touch the closer to reality it gets, but the further left I touch the further from my finger it senses. I hope this makes sence to anyone. there are no calibration settings or apps that I can find. I hope you can help me.

thanks

 

[Percival]

I have a Zeepad (they're also apparently rebranded as Allwinner). The only time I saw a calibration screen was when I did a factory reset. I don't recommend that because it came up in Chinese- finding the language settings was pure dumb luck.

You might try using a stylus. If you don't have one handy try an ordinary #2 pencil, tapping gently but firmly. That means let it rest on the screen for a second (literally, one second) before lifting. I've found that the center of my fingertip isn't quite where I thought it was.

 

[Note]

Hi Karl, did you ever work out how to fix this issue as I'm having exactly the same problem after replacing my screen. It registers a touch correctly in the bottom right hand corner and gets progressively worse moving to the top left.

I've rooted the tablet to use a calibration app which had no effect and tried making changes to the idc file which also had no effect .

From what I can gather the touch screen resolution is incorrect and therefore maps incorrectly to the lcd. There are raw values for the touch screen resolution that you should be able to change to correct this but I can't for the life of me work out where they are or how to go about changing them.