I'm trying to flash OpenWRT onto a Dlink-853 which is currently running Padavan (126.96.36.199). The Web UI doesn't like the header of the OpenWRT sysupgrade file and mtd seems to not work either (see below). Any hints how to proceed? I have searched through the forum, and I saw a bunch of people flashed this device from Padavan to OpenWRT, but no details.
There are a few versions of the hardware... the R1 and A3 revisions are supported by OpenWrt 22.03.5.
The general guidance is this: return to the stock firmware first. Then, flash OpenWrt from there. If you need help getting back to the stock DLink firmware from Padavan, you should ask for guidance in the Padavan support channels.
Take a look at this thread -- it looks like there are some users who have made exactly the same transition.
I don’t know if this is normal for other D-link routers but with my own DAP-1610, only the first stock firmware version was flashable, so try various versions if you don’t succeed at first. You might also be able to flash OpenWrt directly from the recovery gui but ymmv.