MobileRead Forums - View Single Post - Help with unbricking kindle via serial port

yifanlu · 11-14-2010, 03:06 PM

Ok, I screwed up bad and bricked my Kindle 2. I was messing with the Kindle system files, trying to get ubuntu to boot, and I know I messed up something in /etc/init.d and the kindle won't boot up anymore. I know it can still turn on by measuring the voltage of various ports, and I know exactly what file I screwed up to brick it. Now the only problem is fixing it. I'm tried to build an TTL to RS232 adapter, but it wouldn't work. I tried to order one from eBay, but that I think the adapter was DOA. Now, I have some questions before I purchase another adapter. Hopefully someone with experiences with the serial port can answer.

1) If you purchased a working RS232 adapter for the kindle, please send me a link.
2) What is the voltage? I measured GND -> VCC on the kindle and got 2.8V. But adapters are either 3V, 5V, or 5.5V. Which one should I buy?
3) Do I need an external power supply (battery)? I see a lot of people doing this. Why (doesn't VCC provide power)? If so, what type of power supply and what voltage? Where do I connect the power supply if it's needed?
4) Is this right? With the kindle facing down, battery towards the bottom, the order of the pads (left to right) is: VCC, Tx, Rx, GND
5) What's the PuTTY settings?

Sorry for the stupid questions, but I need to be 100% sure before I try again. I don't want to screw up farther and burn the serial port or something. I tried searching, and all threads dealing with serial port aren't detailed enough for me. Thanks.

11-14-2010, 03:06 PM	#1
yifanlu Kindle Dissector Posts: 662 Karma: 475607 Join Date: Jul 2010 Device: Amazon Kindle 3	Help with unbricking kindle via serial port Ok, I screwed up bad and bricked my Kindle 2. I was messing with the Kindle system files, trying to get ubuntu to boot, and I know I messed up something in /etc/init.d and the kindle won't boot up anymore. I know it can still turn on by measuring the voltage of various ports, and I know exactly what file I screwed up to brick it. Now the only problem is fixing it. I'm tried to build an TTL to RS232 adapter, but it wouldn't work. I tried to order one from eBay, but that I think the adapter was DOA. Now, I have some questions before I purchase another adapter. Hopefully someone with experiences with the serial port can answer. 1) If you purchased a working RS232 adapter for the kindle, please send me a link. 2) What is the voltage? I measured GND -> VCC on the kindle and got 2.8V. But adapters are either 3V, 5V, or 5.5V. Which one should I buy? 3) Do I need an external power supply (battery)? I see a lot of people doing this. Why (doesn't VCC provide power)? If so, what type of power supply and what voltage? Where do I connect the power supply if it's needed? 4) Is this right? With the kindle facing down, battery towards the bottom, the order of the pads (left to right) is: VCC, Tx, Rx, GND 5) What's the PuTTY settings? Sorry for the stupid questions, but I need to be 100% sure before I try again. I don't want to screw up farther and burn the serial port or something. I tried searching, and all threads dealing with serial port aren't detailed enough for me. Thanks.