Changing ereader vcom using hex editor

[noobyme]

im a noob Hello,
I've been tinkering around to see try to see if my ereader was worth repairing and after some thankful internet tips from Waldy for figuring out you can run the latest kobo firmwares that can change vcom on older devices and DNSB for telling me about hex editors and the waveform files, I have come to the realization that we can change the vcom possibly on any ereader device so long as you have 2 firmware images running the same firmware but with different vcom values. Open a hex editor and look for the difference between the two... in my case the nia had a difference at offset 0x80030 column 07 and 08, the vcom was represented by "two's complement". I imagine this may be possible even on soldered memory devices and kindles too, if u can use dd to take an image, tho i wonder if it may be corrupted if it is in use while u do that...

I know now however that displays have unique vcoms and unique waveforms, and I still l cannot tell exacttly whats going on because my Kobo Nia Rev C can take any waveform and any vcom value without display issues whereas my Rev A Nia doesnt seem to be able to take any vcom or any waveform and I dont have a matching display for the Rev A so i cant tell what the problem is.
I cannot believe no one has thought of this before... I can see very knowledgeable ppl have come searching for this power before with no success. I the end I couldnt get my display to work without fading for my revision a motherboard though.... and one road block for other devices may be the vcom is represtned in a code that cant be figured out