Need help unbricking a PW1

[knc1]

Originally Posted by palbeda

The reason I said it was that I bought a cheap level converter that should have been able to do it, but it appeared that the impedance was too low to make it work.

s/high/low ?
But yes, low voltage CMOS does not draw much current.
It requires interface circuitry designed/intended for those characteristics.

Geekmaster posted (its indexed) a level shifter circuit, but I think that was about 50/50 luck and engineering.
The 'luck' comes into it when re-using salvaged parts of unknown characteristics - his choice worked for him (his engineering skills are without question).

[RoBoKoP]

I set every thing up and nothing shows at the serial console. =(

[knc1]

Originally Posted by RoBoKoP

I set every thing up and nothing shows at the serial console. =(

A few more details please.

[RoBoKoP]

Configured the adapter to use 1v8 by soldering J1 and J3 and not the others.
Soldered TX and RX like this:

Found here where I should get the 1v8 from.
Used windows to run putty after installing drivers.
Ran, configured => Nothing shows on the console.

The screen still shows the same "Please wait" screen.

Could this be because the device is in recovery mode? (which shows in lsusb)
Is the serial port activated only when the device boots normally?

[knc1]

Originally Posted by RoBoKoP

Configured the adapter to use 1v8 by soldering J1 and J3 and not the others.
Soldered TX and RX like this:

Found here where I should get the 1v8 from.
Used windows to run putty after installing drivers.
Ran, configured => Nothing shows on the console.

The screen still shows the same "Please wait" screen.

Could this be because the device is in recovery mode? (which shows in lsusb)
Is the serial port activated only when the device boots normally?

The serial port is activated when the boot code burned into the SoC is executed - then it is never turned off.
It gets passed (or re-used) by each part of the boot process.
First the SoC
Then u-boot
Then the kernel

Note: Linux is a "Unix like" system, it **will not** run without an operator's console (which is what the serial port is).

Since you only show a diagram, rather than the actual work -
My first suggestion is to re-check your work.

Pay attention to connection problems (or shorts) at the serial port connection pads.

Be sure you have Putty correctly optioned.
(The serial port never changes its speed, that is one thing you need not worry about).

The with the Kindle powered down <<-- means un-plug battery, the only way to power off a Kindle.

Temporary jumper Tx - Rx on your adapter board, you should see every character you type in Putty echoed onto Putty screen.

If that is so -
And nothing is wrong physically with your connections -
Then the Kindle is not running (after you remove the jumper and re-connect the battery).

[RoBoKoP]

I think I killed it: I can't get the 1v8 any more.

While trying to get echo on the serial console, I short-circuited the mobo's TX and RX (and maybe GND) while the battery was connected.
I placed a flat screwdriver on them (and maybe on a metallic plate too), the screwdriver got a little hot, then I remembered I should have removed the battery.

After I removed the battery I short-circuited TX and RX again and could not get any echo.
I measured the 1v8 pin and didn't get a damn thing. So I think it's dead.
The orange LED still lights though.

I'm doing all of this at a friend's place, so I don't take my time doing this. I wish I had electronics gear to do this on my own.

I'll try next time and see if the device would cooperate.

[RoBoKoP]

@▒▒▒&&LN▒▒8-lab126 (Sep 06 2012 - 16:07:56)

CPU: Freescale i.MX50 family 1.1V at 800 MHz
mx50 pll1: 800MHz
mx50 pll2: 400MHz
mx50 pll3: 216MHz
ipg clock : 66666666Hz
ipg per clock : 66666666Hz
uart clock : 24000000Hz
ahb clock : 133333333Hz
axi_a clock : 400000000Hz
axi_b clock : 200000000Hz
weim_clock : 100000000Hz
ddr clock : 800000000Hz
esdhc1 clock : 80000000Hz
esdhc2 clock : 80000000Hz
esdhc3 clock : 80000000Hz
esdhc4 clock : 80000000Hz
MMC: FSL_ESDHC: 0, FSL_ESDHC: 1
Board: Unknown
Boot Reason: [POR]
Boot Device: MMC
Board Id: ?
S/N: ?
Invalid board id! Can't determine system type for RAM init.. bailing!
DRAM: 0 kB
Using default environment

----

Stuck here, doesn't respond to user input

[knc1]

That sure looks like the result of "Erase All" on an earlier firmware (that did not restore the board id).

You need to provide a (proper) board id before it will start up the dynamic ram chip.
You will also need the correct board serial number (which you can get from your Amazon Account "Manage Devices" page).

[RoBoKoP]

I have the serial number, not sure about the board id though.
Is the latter printed on the board or on the back of the device?
I'm not at my friend's place, I left everything at his.

And provided I have the two in hand, how would I proceed next?

[knc1]

It is Christmas day in my part of the world.

[RoBoKoP]

Happy Christmas everyone!

[RoBoKoP]

I did a little bit of research on the forum and found somebody who had compiled their own version of uboot that sets the S/N and board ID for them.

Assuming this is the correct way to proceed, where can I get the source code from?

[knc1]

Originally Posted by RoBoKoP

I did a little bit of research on the forum and found somebody who had compiled their own version of uboot that sets the S/N and board ID for them.

Assuming this is the correct way to proceed, where can I get the source code from?

Duh . . . .
Where on the forum did you find that somebody?
Link please.

[RoBoKoP]

Something like this?
https://www.mobileread.com/forums/sho...&postcount=725

[knc1]

Originally Posted by RoBoKoP

Something like this?
https://www.mobileread.com/forums/sho...&postcount=725

It says: From Amazon sources
So go to Amazon.com source code page.