Cannot flash bootloader image.

[MaciejMalczyk]

I have problem with step 7 - nvflash downloads bootloader image to Nexus tablet but after reboot it does not boot into bootloader even with pwr + vol down. Instead it goes to APX mode. Device have broken system image and it will not boot automatically into system after bootloader flash. Is there any way overcome this? Or maybe i'm doing something wrong?

The only difference that i have in comparison to debrick instructions is flag: "sdram config strap: 1" from 6th step.