The LED is not a reliable indicator of battery status on a bricked kindle. It is controlled by SOFTWARE, not by hardware. In fact, the battery charger is also controlled by SOFTWARE, so bricking a kindle can interfere with charging the battery.
We have had excellent recovery success by charging the battery first. Charge the battery with a wall charger for at least two hours, then use MfgTool to change to fastboot mode (which charges better and faster according to serial i/o messages about battery status during fastboot mode). Charge it in fastboot mode AT LEAST two more hours (preferably overnight) then try again. There are three different people I helped who succeeded ONLY after there battery got enough charge. Without enough, you will see strange behavior, like RUNME.sh not finishing, or fastboot not working, or MfgTool starting to download u-boot to the Kindle but never finishing.
So, charge it enough to get into fastboot mode, then charge it some more. There is a good chance you WILL be able to get to diags, from which you CAN repair you kindle using USB drive export and a custom RUNME.sh launched by data.tar.gz, to fix your "custom" problem...
I have my touch connected to a serial port now, and the ONLY serial i/o messages I see during and after booting to fastboot are battery voltage messages, which show a steady quick charge up to 4.190 volts, where it stabilizes (my k4nt stabilizes at 4.171 volts). Now that I have a good battery charge, I will try debricking it again.
Here is my serial port output after booting fastboot with MfgTool:
Code:
Boot 2009.08-lab126 (Feb 19 2012 - 05:03:11)
CPU: Freescale i.MX50 family 1.1V at 800 MHz
mx50 pll1: 800MHz
mx50 pll2: 400MHz
mx50 pll3: 216MHz
ipg clock : 50000000Hz
ipg per clock : 50000000Hz
uart clock : 24000000Hz
ahb clock : 100000000Hz
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: Whitney WFO
Boot Reason: [POR]
Boot Device: MMC
Board Id: 0061XXXXXXXXXXXX
S/N: B011XXXXXXXXXXXX
*** TODO: Dump protected MMC here ***
DRAM: 256 MB
Using default environment
In: serial
Out: logbuff
Err: logbuff
Quick Memory Test 0x70000000, 0xfffe000
POST done in 13 ms
BOOTMODE OVERRIDE: FASTBOOT
Hit any key to stop autoboot: 0
U-Boot 2009.08-lab126 (Nov 03 2011 - 11:56:58)
CPU: Freescale i.MX50 family 1.1V at 800 MHz
mx50 pll1: 800MHz
mx50 pll2: 400MHz
mx50 pll3: 216MHz
ipg clock : 50000000Hz
ipg per clock : 50000000Hz
uart clock : 24000000Hz
cspi clock : 54000000Hz
ahb clock : 100000000Hz
axi_a clock : 400000000Hz
axi_b clock : 200000000Hz
weim_clock : 100000000Hz
ddr clock : 200000000Hz
esdhc1 clock : 80000000Hz
esdhc2 clock : 80000000Hz
esdhc3 clock : 80000000Hz
esdhc4 clock : 80000000Hz
MMC: FSL_ESDHC: 0, FSL_ESDHC: 1
Board: Whitney WFO
Boot Reason: [POR]
Boot Device: MMC
Board Id: 0061XXXXXXXXXXXX
S/N: B011XXXXXXXXXXXX
I2C: ready
DRAM: 256 MB
Using default environment
In: serial
Out: serial
Err: serial
POST done in 2 ms
Battery voltage: 4058 mV
BOOTMODE OVERRIDE: FASTBOOT
running cmd: fastboot
Entering fastboot mode...
Battery voltage: 4063 mV
USB speed: HIGH
Connected to USB host!
Charger disconnect
USB speed: HIGH
Connected to USB host!
USB configured.
Battery voltage: 4166 mV
Battery voltage: 4162 mV
Battery voltage: 4162 mV
Battery voltage: 4162 mV
Battery voltage: 4171 mV
Battery voltage: 4176 mV
Battery voltage: 4166 mV
Battery voltage: 4162 mV
Battery voltage: 4171 mV
Battery voltage: 4176 mV
Battery voltage: 4185 mV
Battery voltage: 4185 mV
Battery voltage: 4166 mV
Battery voltage: 4180 mV
Battery voltage: 4180 mV
Battery voltage: 4185 mV
Battery voltage: 4190 mV
Battery voltage: 4194 mV
Battery voltage: 4190 mV
Battery voltage: 4190 mV
Battery voltage: 4194 mV
Battery voltage: 4190 mV
I ONLY see these battery messages while in fastboot mode. In other modes they kindle just aborts my repair attempts faster and faster until it is completely dead and cannot be seen by MfgTool. It does NOT charge on USB in main or diags mode unless on a wall charger, and then not very quickly or reliably.
I think that the reason is because fastboot loads the full bist u-boot from mmc (why there are two u-boot sets above), and the larger bist build has better battery charging code in int. Booting to main or diags just uses the little u-boot that was loaded into RAM.