Acer Iconia w4 820 Touch Screen Top one third not registering touches, ghost touches
I recently removed my Acer Iconia Tablet from my closet after six months, and the battery had been exhausted to the point where even the time had been reset on it. Anyways I charged the battery using a 5V 2A charger and it charged okay. I powered it on and noticed peculiar false ghost touches towards the bottom of the screen, and noticed that the top one third of the screen was not registering touches. After a little while the false touches disappear and then, as I managed to login to the device using the bottom two thirds of the screen, I noticed that the top one third wasn't responsing to touches. The tablet was secure in my closet , so no one else tampered with it. Now I've tried the following as solution after researching thoroughly but nothing has worked thus far:
1. Update HID touch interface drivers, BIOS firmware to 1.6, 2. Upgrade to Windows 10. 3. Reset Windows 10, reset Windows 8.1 4. Downgrade to Windows 8.1, 4. Upgrade back to Windows 10. 5. Connecting a mouse. 6. Connecting HDMI 7. Trying alternate chargers. 8. Unistalling and then resinstalling HID touch interface device in device manager. 9. Unseating and reseating display flex connectors, Battery Power cable connectors to motherboard and display to motherboard connector buses inside the tablet.
Still no solution..what I first need to know if this is a hardware or software issue. I suspect software, since my internal clock battery had gone unsynced after the six month period, and since I've already tried basic hardware seating and unseating on the cable buses. Is there a touch screen testing software in BIOS that I can use like on Android tablets? Can anyone also advise if I should go for a new tablet or buy a replacement touch screen at USD 118 from the Acer Service center? How do I display output to full HD 1366X 768 via the HDMI cable?