DSL-2750B T1 - Uploading failed. The selected file is illegal

Hi There,

I tried to use Method 1: via OEM firmware for

D-Link DSL-2750B T1 Firmware Version :AU_3.08
the file I downloaded from
Firmware OpenWrt Install URL:
http://downloads.openwrt.org/releases/19.07.2/targets/brcm63xx/generic/openwrt-19.07.2-brcm63xx-generic-A4001N-squashfs-cfe.bin

When I click firmware updfate using above file, I got the following error message:
Uploading failed. The selected file is illegal.

Please help.

Is this the same procedure as described in the techdata?

Comments: Flashed via CFE recovery (hold down reset when powering up device)

With Broadcom chipset (see the warnings on the top of the techdata page), 320MHz CPU, 8MB flash and 64MB ram this device won't get you far, so consider that before you invest some time on it.

Hi Tendy,
Yes, I followed Techdata for D-Link DSL-2750B T1.
This is a spare route so I just want to see if it works for wifi extender after install openwrt firmware.