Brick on WP76xx

Hello, we are using the wp76xx on mangoRedOh board;
We tried to erase all the flash mtd parts and test that our generated image has all the functional parts.

Under /proc/mtd we saw 20 mtd parts like:
mtd0 … " sbl"


We deleted it by:

flash_eraseall /dev/mtd0

but after reboot the device cant boot and show nothing at the ttyUSB0 terminal.
Booting to recovery mode by using the hw dip switch (TP1 pin on mangoRedOH) didnt help either.

lsusb at the devStation shows:

05c6:9008 Qualcomm inc Gobi Wireless Modem (QDL mode)

and swiflash to burn the spk image wont work either.

How can we get to recovery mode or get out of that brick please?