Uboot/mtd_write issue on a5-v11 router (battery version)

Would anyone knowledgeable about the a5-v11 unmarked router or uboot/mtd be able to help me with a problem im getting trying to write the bootloader.

Following the guide from OpenWrt as i have the Qualcomm web interface i need to write uboot to the device before i can do much else, however when connected to my network with a usb drive attached to write the files from via telnet i just get.

# mtd_write write /mnt/uboot256.img Bootloader
Unlocking Bootloader ...
Writing from /mnt/uboot256.img to Bootloader ...  [w]Post-Write check failed.

no further explanation given, so im not sure if it wants something signed or what you, i've tried multiple versions of uboot and re-downloaded them to make sure to no avail.

I've tried to investigate the possibility of using UART to write to it but with having the battery version of the unit shown at the bottom of the aforementioned OpenWrt page the UART pads are unknown to me.