Kobo Nia Screen replacement

[WhiiskeyTango]

Hi all!

I have a kobo Nia with a cracked screen. I've replaced ereader screens before, so that would not be a problem for this one.

My Nia currently has a screen with the code ed060xh7. When I search for this particular code, I only find replacements for the "Pocketbook Lux 3".

When searching for a Nia Screen replacement, I find suspiciously similar screens. Only difference it the price. The Nia screens are seemingly a tad bit more expensive.

Both the Nia and Lux 3 are 1024x758, both are 6", both are 212ppi. Seems like the screens are the exact same.

Has anyone else replaced a Nia screen, and found something similar? Think it would be just fine to order the (cheaper) Pocketbook Lux 3 screen?

[sirwb13]

I just changed the screen on my kobo nia and everything seems to work fine except there's a fading issue. The new screen vcom is different from the old screen, which is what seems to be causing the fading issue. I haven't been able to figure out yet how to change the vcom setting. If you can special request the same vcom new screen as your old, it'll probably work better. Or atleast until someone figures out how to adjust the setting on a nia. Both my glo hd and libra h2o don't have the vcom showing in the ifixit repair guide for the clara color and b&w

[JSWolf]

Originally Posted by sirwb13

I just changed the screen on my kobo nia and everything seems to work fine except there's a fading issue. The new screen vcom is different from the old screen, which is what seems to be causing the fading issue. I haven't been able to figure out yet how to change the vcom setting. If you can special request the same vcom new screen as your old, it'll probably work better. Or atleast until someone figures out how to adjust the setting on a nia. Both my glo hd and libra h2o don't have the vcom showing in the ifixit repair guide for the clara color and b&w

You might have to wait for a new firmware to be able to change the vcom.

[WhiiskeyTango]

I got the same result; a new screen with a fading issue. Unfortunately, it seems like there is nothing that can be done right now. I really hope that there will be a new firmware update that will allow us to change the vcom settings

[JSWolf]

Originally Posted by WhiiskeyTango

I got the same result; a new screen with a fading issue. Unfortunately, it seems like there is nothing that can be done right now. I really hope that there will be a new firmware update that will allow us to change the vcom settings

I don't know if this is specific to the newly released devices, but 4.39 on the new devices does allow you to change vcom.

[grimorie]

Originally Posted by sirwb13

I just changed the screen on my kobo nia

Hi! May I know where you bought your screen for kobo nia?

[Waldy]

After replacing the display or with someone else's image recorded on the µSD card, you can try this method to change the vcom value.

1. Make sure that you have firmware 4.38.23171 installed on your Kobo Nia, if not, update it.
2. Now install the firmware kobo-nia-temporary-update-4.41.23145.zip on top of 4.38.23171.
In this firmware, I simply changed the drivers so that it would install on Kobo Nia and it would be possible
change vcom value.
3. Change vcom values ​​following these instructions: https://www.ifixit.com/Guide/How+to+...Display/170983
4. After the change, do a hard reset using the button or turning on devmode.
Developer options - Factory reset your eReader.
5. Update to the latest firmware (currently 4.38.23171).

I tested this on Kobo Nia, but do so at your own risk.

[noobyme]

Mine was fully adhered with an entire sheet of adhesive rather than strips present on other models, I ended up buying a new Nia used instead. I even considered making a replacement backplate which I made in Cad tho the placement of some features were slightly off because I had to measure it after I had hammered it, but the cost was not worth it or the time considering I found a used one for almost the same price as a new screen. I tried hammering, using heat, peeling chip by chip. I did not try soaking in solvent but I didn't think it would work because the exposed surface area was very low, is that what you guys did?

[noobyme]

Originally Posted by Waldy

After replacing the display or with someone else's image recorded on the µSD card, you can try this method to change the vcom value.

1. Make sure that you have firmware 4.38.23171 installed on your Kobo Nia, if not, update it.
2. Now install the firmware kobo-nia-temporary-update-4.41.23145.zip on top of 4.38.23171.
In this firmware, I simply changed the drivers so that it would install on Kobo Nia and it would be possible
change vcom value.
3. Change vcom values ​​following these instructions: https://www.ifixit.com/Guide/How+to+...Display/170983
4. After the change, do a hard reset using the button or turning on devmode.
Developer options - Factory reset your eReader.
5. Update to the latest firmware (currently 4.38.23171).

I tested this on Kobo Nia, but do so at your own risk.

update:I was wrong vcom can be changed with this method! so the kernel does have this ability after all??? but it may not fix ur fading issue

Dont bother with this it didnt work; I have both a Rev A and Rev C Nia motherboard, I was able to update to 4.41 on both, although I now know the A and C have different kernels and waveforms despite the motherboards being able to recieve the same firmware upgrades. Switching sd cardsbetween them results in failure to boot on either. something is different when it comes out the factorysoftware wise, Szybet on github made mention of something similar of kernel sources being outdated for Rev C Nia. the firmware says it has changed the vcom but the display fading remains, I thought maybe it was because I damaged the motherboard because I only have one screen but 2 boards, one of which has the correct vcom already, after changing the vcom on the one that was correct it didnt even have a fading issue, meaning that it was never changed. It was 2.57 and 2.52; I changed 2.57 to 2.52 and 2.52 to 2.57. Also in the update folder you dont need the upgrade folder or even the drivers folder, since we already have those by being on 4.38? Was that a precaution? So the lesson is that the vcom change requires the correct kernel or something uboot?
Also be careful, I read dust can cause artefacts on e ink screen, after doing many board changes to make sure I wasnt just doing something incorrectly, theres an exposed area of the display when you remove the pcb and some dust accumulated, no issue at first but after I wiped with a damp cloth now it seems artefacts like grainy appears after a while. Sigh. Wait im not sure if im crazy or if im staring too closely... it seems like i cant see it anymore bc it seems to be permanently in the grainy state, in eed anew screen to compare with... hmm seems to be gone, it was similar to the fading

Thus the only way to truly use a new screen is request a display with the same vcom, or find an sd card image with the required vcom, I wonder what the distribution of vcom values is like, if its a normal distribution with a peak in the median then finding a correct one wont be too hard but still needs many ppl to image their sd cards and note the vcom on the display

4.38.23171 Rev C waveform 320_R387_AD6F21
4.38.23171 Rev A waveform 320_R390_AD4321

edit:hmm so waveform is unique to each panel... i now know waveform is stored at sector 14336 thanks to postmarketos kobo nia wiki page. copying from that sector until the first partition results in a change of waveform, however copying from sector zero to first partiion leads to change in vcom as well. i wonder if changing vcom is possible after all? i need to test by copying the waveform to my rev a mb

[Waldy]

I think you expect too much from the VCOM values.
Take a photo of what the screen looks like when reading, maybe everything is OK with you.)
I swapped SD cards on many devices and did not notice much difference. It is very rare that the font looks paler.
I have prepared an image for you from 4A2 from such a device (there are others):
https://ibb.co/SwvB6KS3
https://ibb.co/Y4gbzWwp
https://ibb.co/XfCqGzzW
4C1 I have only three devices, tell me from which one should I create an image:
https://ibb.co/4nKPzL2C

[noobyme]

Originally Posted by Waldy

After replacing the display or with someone else's image recorded on the µSD card, you can try this method to change the vcom value.

1. Make sure that you have firmware 4.38.23171 installed on your Kobo Nia, if not, update it.
2. Now install the firmware kobo-nia-temporary-update-4.41.23145.zip on top of 4.38.23171.
In this firmware, I simply changed the drivers so that it would install on Kobo Nia and it would be possible
change vcom value.
3. Change vcom values ​​following these instructions: https://www.ifixit.com/Guide/How+to+...Display/170983
4. After the change, do a hard reset using the button or turning on devmode.
Developer options - Factory reset your eReader.
5. Update to the latest firmware (currently 4.38.23171).

I tested this on Kobo Nia, but do so at your own risk.

Originally Posted by Waldy

I think you expect too much from the VCOM values.
Take a photo of what the screen looks like when reading, maybe everything is OK with you.)
I swapped SD cards on many devices and did not notice much difference. It is very rare that the font looks paler.
I have prepared an image for you from 4A2 from such a device (there are others):
https://ibb.co/SwvB6KS3
https://ibb.co/Y4gbzWwp
https://ibb.co/XfCqGzzW
4C1 I have only three devices, tell me from which one should I create an image:
https://ibb.co/4nKPzL2C

wait sorry i didnt mean to ask you to provide more images thanks though, i have a perfectly working nia with matching display from factory, i just merely wanted to test if vcom values could indeed be changed. i also have another nia motherboard without adisplay, that way icould test the vcom change twice. changingthe vcom did nothing to either board,before and after
thats why ibelieve thereis no abiliy to change vcom present. unless vcom was changed and the problem with fading screen was due to waveform being different? to b clear, the extra motherboard did have the fading screen issue but the perfectly working one did not

btw did uedit the waveform name along with th3 serial number for the rev a 276 img u sent me? the waveform is ad3421 while on mine it is ad4321, theyre soclose icant tell if it was a typo or what. ive juet realised u changed the serial bc giving that info is abad idea isnt it. okay after checking various images , waveform numbers are unique to each device/panel batch in addition to having unique vcoms

[Waldy]

I changed only the serial number using HxD - Hex Editor.

[noobyme]

Wierd, I just tested a rev c image with vcom 273 and a different waveform value, despite that my display is for 253 there is no fading issue! Whatgives? Was it my motherboard the problem after all? Yet the ppl above who replaced their display do have the fading issue... damn im not surehow to proceed now to further gwin more information id need another revision A Nia or a display with the right vcom...

itested ur image with vcom 281, as well. no fading here. My hypothesis is vcomseems to matter only for revision a boards, or my revision aboard is damaged
or rev a and rev c have diff vcomstorage methods, perhaps rev c stores it onsd card rev a stores on another chip somewhere

[noobyme]

Waldy have you ever tried switching sd cards between your rev a devices? did it result in fading?

Hmm after more testing, I put a rev a waveform onto rev c with matching display, no fading, changed vcom so its no longer matching still no fading
Put matching display waveform from rev c onto rev a board, fading exists, change vcom using the 4.41 method, fading still exists.
I then try putting rev another rev c waveform onto the rev c board from someone elses image, right after testing the a board. surprise there was fading! but only temporarily... after a few reboots it was gone. i seem to be missing crucial information, cant tell if its my rev a board problem or not. maybe rev a and rev have different waveforms to match the display and i need a rev a with matching display and can only use that waveform to get it, but then why is rev c fine even iwith wrong waveform and vcom??

I verified vcom was changing by checking before and after sd card images, 2 bytes of data changed at offset 80030 column 07 and 08. so now knowing this, seems like all you need is 2 images of the firmware to find where the vcom is located opening a new avenue to change vcom possibly, if u can figure out what the number is supposed to be. i feel its odd surely someone has thought of this before... the same change was identified in same images with diff vcom

sudo dd if=/home/NiaC257waveform.img of=/dev/sdX skip=14335 count=34816 seek=14335 status=progress
command to copy waveform only, the vcom is located at offset 80030. thanks to postmarketos wiki for telling its located at sector 14336
FF04 252 FEFF 257 FF04 252 FEFF 257 FEEC 276 FEE9 279 FEEF 273 FEE7 281
i verified the vcom values by changing 252 to 257 and 257 to 252, giving the same hex values
GEE AFTER putting teh values into a converter, seems it is represtned by something called two's complement
https://www.rapidtables.com/convert/...al.html?x=FEFF