Toshiba XE1 Video Output Issue

Hey folks, So I picked up a cheap XE1 which was on an old troublesome firmware with the freezing on boot/read issues. The player was finicky but ultimately did work. I updated to 2.5 from the ISOs on archive.org but now my TV just shows an unsupported resolution error. I have tried everything except switching to composite and can't get the picture back. I have gone through both the EUR and AUS versions of firmware and even tried moving up to 4.0 but no difference.

Anyone have any idea what to do? I have managed to work through the menus blindly to switch the resolution between all options but still nothing. I was hoping there were some service button combinations to force some magic to happen, but the service manual just says "replace main unit" after the very basic checks...