Problem restoring NAND Flash

Hi,

We have ~200 units of mini2440 with supervivi version 1026. I developed
WinCE 6.0 in a Mini2440 (supervivi 945), in this board I loaded supervivi
(945), nboot and NK.bin. Then, I configured some thing in Windows, then,
backup NAND flash.

With this image of NAND, we restore NAND flash of all 200 units, but just
6~7 boards doesn't boot: just load nboot, but LCD freeze with yellow bar. I
tried booting from NAND and from supervivi, but always happen the same. If
I load again supervivi (always version 945, but board has 1026), nboot and
NK.bin, it works! I restarted it many times and always works. Then, if I
backup this NAND Flash and loaded again, it is still working!

Why could happen this? This last image must be equal than first one, and I
cannot have 2 different images that really doesn't have any difference :S

Please, any comments helps me. Thank you!

Leo

Hello Leo, 
With a board that doesn't work after NAND restoration, you should try to
just load nk.bin and see if it works, then just nboot and see if it works.
I wonder if NAND flash backup/restoration includes the NAND flash
bootloader...
Domodom

I just did that: I restored NAND flash and, as I expected, it doesn't boot.
Then, I reloaded just nboot, nothing. Then, resstored NAND again, reloaded
supervivi, and nothing. And finally, when I reloaded just NK.bin, it works!

Another issue of this boards: all has bad sectors in flash, so, I think
that as I'm loading an complete NAND flash from other board with no bad
sectors, some critical information of OS could be lost. But when I load
NK.bin, supervivi can partition flash isolating those sectors.

This is just a theory... I'll be loading just this board from NK.bin.

Thank you!
Leo

PD: Wow! supervivi 1026 improves A LOT time of loading NK.bin (formating
stage). From about 5 minutes (in 256 Mb board) to ~30 seconds. With next
boards, we're not using NAND flash recovery :P