It's possible. Only BIOS Chip flash. I did. That. It's working. But I don't have V.3 file. I have V.2. Now my device V.2. BEFORE V.3. IF ANYONE Have dump file C60 V.3. Please share to me.
I know this is an old thread, I have OpenWrt 18.06.5 r7897-9d401013fc running on my Archer C60 v3 router. Just curious if anyone knows how to upgrade to the latest Openwrt version 23.05.0. I get 'The uploaded image file does not contain a supported format. Make sure that you choose the generic image format for your platform.'
Tnx
You're probably on an old ar71xx build and need to force the migration to ath79 (not keeping settings!). There should be information about that in this forum, maybe even in connecting with this device. Take your time to read up on the details.