K3 Kindle K3 upgrade and How to change screen flash frequency in turning page

Hi All,

My Kindle model: Kindle k3g.
Firmware version v3.3
Jailbreak v0.11.N


I could not tolerate my Kindle K3g continuously restarting and run out of power in several days when WIFI is on. The cause is that Amazon will automatically push the update to my kindle

I was expecting to upgrade the firmware version from 3.3 to 3.4 after upgrade JB, SS and USBNet to the latest version (B v0.13.N, SS v0.47.N, Python 0.14.N, Fonts v5.16.N, USBNet v0.57.N ), but the firmware upgrade failed.

After that, the screen flashes every time when turning page which is really annoying.I did initial jailbreak on my kindle K3g 5 years ago, I remember there was a parameter that we can change on a jailbreaked Kindle K3 to prevent screen flash every time when turning a page, but I cannot recall this parameter and also failed to get it by googling.

Appreciate someone can answer any of the questions:help::help:

What the parameter is?
where the configuration file is located?

If this is a debug parameter, how to apply the change?

Does anyone successfully upgrade kindle k3g firmware from v3.3 -> 3.4 -> 3.42 without a factory reset without JB uninstalled?