Quote:
Originally Posted by Yorker
Great i"ll test it out but 3 questions to go
1. I saw someone solder a resistor to scale down 3.3v to 1.8v i thought it's mandatory otherwise it won't work or fry
2. i'm wondering how to connect this as i only have jumper cables with this adapter so i guess cut one end of one cable and solder the points while keeping the jumper on the other end and connect to the pins?
3. Assuming it works the next step would be to get and copy the correct image? i need that exact one? i didn't update the kindle ever if that matters
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1. It depends on the Kindle model concerned.
I have a Kindle Touch (two of them, one dead) and a Kindle 7th generation (KT2).
The Kindle Touch wouldn't accept 3.3 volts (and I tried), requiring Geekmaster's level-shifter circuit, or at least a resistor (and I don't have one, so I left them without serial port access). It didn't burn out or anything when I connected the 3.3v adapter, but didn't send any output either.
But the 7th gen Kindle happily accepted the 3.3v adapter without an issue. Check around here to see if your Kindle Paperwhite model is
3.3v-tolerant. I'd guess that it is indeed. But is it really difficult to wire a resistor? You don't even have to solder it, you just wrap the cables around its pins.
2. That's like my setup. In the picture below from my 7th generation Kindle, I took another jumper cable from an old ATX case (had to settle for two-pin, more on that later) and soldered it to the Kindle to create a permanent serial port, then glued it to the sides so it won't move around when the Kindle is closed.
Then, when I need serial access, I would connect Tx and Rx to these two, and ground is from a third, bare-ended jumper cable wrapped around a Kindle motherboard screw.
3. No, not that fast. You first need to read the serial output to find out what's the issue. If it's eMMC failure, then what good would copying a new image be? But on the other hand, and since you never updated that Kindle before, it might just be a borked OTA update, done behind your back and interrupted for some reason.
You need the image for your Kindle model. But since you're on the serial port, it isn't really a mortal sin to copy the wrong image.
