ZTE 286D revert to factory

Installing and Using OpenWrt
1

Recently i tried my hand in flashing openwrt on zte286d with success ZTE-MF286D modem problem unfortunately the internal modem did not work as expected. how do i revert back to factory stock, i do have the MTD back of the blocks.

2

For similar ZTE device, I usually restore the UBI partitions. This is for the MF287, you need to adapt the partition names and sizes according to your device. The instructions assume that you have booted an initramfs version of OpenWrt, it doesn't work with the persistently installed version. $kernel_length and $rootfs_size are the sizes of the back up files.

Important: The backup was taken with

cat /dev/ubi0_0 > /tmp/ubi0_0 # Kernel
cat /dev/ubi0_1 > /tmp/ubi0_1 # rootfs

This won't work if you backed up the /dev/mtd* partitions directly.
Restore (14 needs to be replaced by the mtd partition number of the underlying device):

ubiattach -m 14
ubirmvol /dev/ubi0 -N kernel
ubirmvol /dev/ubi0 -N rootfs
ubirmvol /dev/ubi0 -N rootfs_data
ubimkvol /dev/ubi0 -N kernel -s $kernel_length
ubimkvol /dev/ubi0 -N ubi_rootfs -s $rootfs_size
ubiupdatevol /dev/ubi0_0 /tmp/ubi0_0
ubiupdatevol /dev/ubi0_1 /tmp/ubi0_1

If you backed up the mtd partitions, you may or may not be able to restore the device. I tried it once and it didn't work, because of bad blocks on the NAND - something that UBI takes care of.

3

Last time I simply flashed mtd8 and mtd9 from OpenWrt console.
Note that this restoration will affect the router only, not the modem.

4

Yeah, pretty sure I've seen posts where people only overwrite mtd8 and 9.

6

Yes , i can confirm ,that from OpenWRT it is enough to flash mtd8 and mtd9 with commands:

mtd write /tmp/mtd8.bin /dev/mtd8
mtd write /tmp/mtd9.bin /dev/mtd9

and cut the power off ,and connect again after some seconds. Did that few times recently.

1 Like
7

That worked on 2 out of 3 MF282 (or was it MF287?) devices last time I tried. The third one had a bad block in this area and wouldn't boot afterwards. The UBI method posted above worked reliably on all my devices.

1 Like
8

I have backed up only mtd parts

9

is there guide for this?