[Acer Iconia A500] Moscow Desire:
One of my counterparts in Germany asked me to post it here. All credit goes to opec. This has been covered a few times, but I like the detailed scenario.

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ERROR: Can´t installl hacked ICS Bootloader

I tried installing Hacked ICS Bootloader in Order to get Moscow Desire´s "Alexandra V a501 ICS 4.0.3 ver 1.4 Final" running on my a501.

The following ways of flashing could get the hacked bootloader on my a501:

"Afterota for A600/G100W" (http://xdaforums.com/show....php?t=1675939),

"blackthund3r´s ATX flash tool A500APXFlash.exe" (see "Automated flashing tools" at http://xdaforums.com/showthread.php?t=1622425")

"Manual flashing via nvflash" (see Manual flashing at http://xdaforums.com/show....php?t=1622425)

Trying to flash with this tools always brought me to a Command Promt saying:

Nvflash started

[resume mode]

APX flash tool hang when it tired to Format Partition 4 etc.

and then doing nothing even if i let it stay for hours. No Information or Error so long.

When i tried flashing manualy (see link above)i finaly saw an error:

failed executing command 25 NvError 0x120002

command failure: sync failed (bad data)

bootloader status: partition table is invalid, missing required information

e: 14) message: nverror:0x4 (0x4) flags: 0

So it seemed however that the partition table on my a501 got messed up. Asking google for "failed executing command 25 NvError 0x120002" brought me to an answer "lcd047" posted on tegraowners (http://forum.tegraowners.com/viewtop...p=15285#p15331)

He desicrbes same problem with messed up partition table an restoring it with timmyDean´s root-3.2.1-V4.7z (http://xdaforums.com/show...&postcount=1):

lcd047 wrote:

"I downloaded timmyDean's root-3.2.1-V4.7z

I booted the tablet (in APX mode) and I connected the USB cable to it

in the directory root-3.2.1/Image I run the command

nvflash --bct flash.bct --setbct --odmdata 0x100c0105 --configfile flash.cfg --create --bl bootloader.bin --sbk (your sbk number after converting your UID number) 0xXXXXXXXX 0xXXXXXXXX 0xXXXXXXXX 0xXXXXXXXX --go

without rebooting, I flashed the v7 bootloader and recovery as per the bootloader thread; since the partition table was restored at the previous step, the operation now succeeded;

I rebooted the tablet in recovery, and proceeded to wipe the data and flash a ROM the usual way.

And that worked for me. After flashing, my a501 did a automated reboot, i quickly killed the reboot by holding the Power Button (guessing killing the reboot is not realy necessary because the booting shouldn´t mess up the partition table again) and then brought the devive back to APX Mode (Holding Reset and Power for 3-4 sec. then releasing Power and after 1 second relesaing Reset).

Then i flashed the hacked bootloader via blackthund3rs APX flash tool (see link above).

Then i installed Alexandra V as Moscow Desire descirbes (see "To Install" at http://xdaforums.com/show....php?t=1635577)

It took my 2 days of trial and error, but finaly give me a nice working Alexandra ROM on my a501!

Hope this helps people having the same issues.

Thanks to Moscow Desire, civato, blackthund3r, gersma, zeroNull, lcdß47, timmyDean

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Note from MD. You guys take note of this. Sometimes, when you get corrupted partition tables, you may have to go back to an HC stock bootloader to get them fixed. Of course there are other methods, but require some indepth knowledge, and this method most people can do easily.

MD