[kpoviv]

Originally Posted by Junket

First we need to look for signs that the battery is charged. Nothing else will work if the battery is actually discharged, defective or unconnected. Ideally we'd like to measure the battery voltage with a meter or install a serial port connection to see if the processor is running. But basics first.

You charged it for 20 hours which is sometimes necessary to charge a weak battery.

Did the LED (power light) stay solid amber while charging?
Did the LED eventually turn green or not?
With the USB cord disconnected, what does the LED do when you try to turn it on with the power switch?

There are several "8th gen" Kindle models, you appear to have a Kindle 2 (2016) which is usually referred to as a KT3 model here.

With the USB cable disconnected, press and hold the power button for about 30 seconds. You should see the the LED turn amber and blink four times. You can let go of the power switch after you see it blink four times. Or let us know if it doesn't blink so we can see where to go next. You sort of described this already but it wasn't entirely clear to me what you observed.

When I left the kindle charging his battery yesterday, the color of the light was orange, 2 hours, 30 minutes passed and the light changed to green (charged battery) and I left him charging the battery until the hours we agreed (20-21 hours) .
Disconnect the cable and press the button for more than 40 seconds. While the button is pressed the light turns on in green for 2 seconds, then flashes 2 times in the same color (green) and then automatically changes to orange, flashing in that color 5 times. And that whole pattern is repeated 4 more times during those 45 seconds.
I just tried to press and hold for 30 seconds with the cable on and something similar happens with no cable connected, with the difference that when I release the power button the light turns green.
*I have a kindle touch 8th the motherboard model is "30-001931"

The last photo I uploaded is not from my kindle, it is from another kindle old of some unknown user of another forum that the only way to solve the freezing of his screen was by touching the motherboard. My Kindle is the one above where you can see two photos together.