Kobo Nia touchscreen not working

[htop]

Hey,

I bought a faulty Kobo Nia at a really good price. The visual condition of the device is very good, the screen is fully functional, but for some reason, the touchscreen is not working at all. I would like to request help in debugging and resolving the issue.

I have disassembled the device to access the SD card with the firmware. I examined the contacts to check if the device had been exposed to any liquid or if the ribbon contacts were corroded, but them are in good condition.

The device came to me reset to factory settings. While tinkering with the firmware, I managed to restore the device to its factory state, but it did not fix the touchscreen issue.

By accessing the firmware, I configured the WiFi and installed OpenSSH server from NiLuJe, which allows me to have shell access on the e-reader. Through this, I discovered that the Linux on the e-reader recognizes the touchscreen as an input device:

cat /proc/bus/input/devices
I: Bus=0019 Vendor=0001 Product=0001 Version=0100
N: Name="gpio-keys"
P: Phys=gpio-keys/input0
S: Sysfs=/devices/platform/ntx_event0/input/input0
U: Uniq=
H: Handlers=event0 
B: PROP=0
B: EV=13
B: KEY=100000 0 8000000 0
B: MSC=8

I: Bus=0018 Vendor=0000 Product=0000 Version=0000
N: Name="elan-touch"
P: Phys=
S: Sysfs=/devices/virtual/input/input1
U: Uniq=
H: Handlers=mouse0 event1 
B: PROP=0
B: EV=b
B: KEY=400 0 4 0 0 0 0 0 0 0 0
B: ABS=2650000 1030003

I also checked if it was a virtual device by disconnecting the touch panel, rebooting the e-reader, and observing that the system no longer recognized the Elan device. This indicates that the touch panel is at least being identified by the system.

I attempted to use evtest to monitor the event1 device, but I only received complete silence:

evtest /dev/input/event1
Input driver version is 1.0.1
Input device ID: bus 0x18 vendor 0x0 product 0x0 version 0x0
Input device name: "elan-touch"
Supported events:
  Event type 0 (Sync)
  Event type 1 (Key)
    Event code 258 (Btn2)
    Event code 330 (Touch)
  Event type 3 (Absolute)
    Event code 0 (X)
      Value      0
      Min        0
      Max     1024
    Event code 1 (Y)
      Value      0
      Min        0
      Max      758
    Event code 16 (Hat0X)
      Value      0
      Min        0
      Max     1024
    Event code 17 (Hat0Y)
      Value      0
      Min        0
      Max      758
    Event code 24 (Pressure)
      Value      0
      Min        0
      Max     2048
    Event code 48 (?)
      Value      0
      Min        0
      Max        2
    Event code 50 (?)
      Value      0
      Min        0
      Max        2
    Event code 53 (?)
      Value      0
      Min        0
      Max     1024
    Event code 54 (?)
      Value      0
      Min        0
      Max      758
    Event code 57 (?)
      Value      0
      Min        0
      Max        2
Testing ... (interrupt to exit)

I am currently stuck at this point and wondering what to do next. I am unsure how to electrically test the touchscreen panel. The issue is also quite specific, and I have been considering whether the touch controller chip may have been damaged, and if it's worth trying to order a new one and change it in (ELAN EKTF2232ALW chip). I wouldn't even want to attempt replacing the touch panel, and I'm not even sure if it's possible to purchase one separately.

Do you have any suggestions? Or has anyone encountered a similar problem here?

[Szybet]

No chance to repair it, propably. If you want to tinker, here are some suggestions:
- Maybe there are some I2C commands you could send, maybe some calibration, some informations idk, just to see if the chip responds in a sensible way. You need to look at the driver code
- Reflow the chip
- scrap open where the flex cable goes and check if the connections are good

And at last, the most reasonable way: Inkbox supports USB keyboard and mouse, it's tricky but could prevent turning the device into electronic waste

If you plan to sell it if none of the options work for you, for a cheap price I would be interested.

[htop]

I will try to reflow the chip and maybe order the new one.