Not sure if there is any help that can be given as I suspect this is a video encoder issue.
First of all thanks for the fast reply
if you have backed up your EEPROM from each xbox, I would unlock the hard drive from the working xbox, and re-lock it with the eeprom from the not working box and see if it works suddenly once you have the new hard drive in. you can then unlock it and re-lock with the original eeprom.
When using SCART (RGB) check the UnleashX Settings > Video Settings > Filter and Soften levels.
i don't think that it would come down to an encoder issue. I've never heard of it being overly problematic when trying to get HD out of the box.
Just ran across this article. Might be helpful
Guys a little update, i've burned a frosty recovery disc. Now when i boot the disc at the boot in 576i 50hz, navigate to file manager, open evox.xbe to boot the SID menu, navigate through the file manager of the SID in the baldur's gate folder and launch it through the xbe the game starts correctly in 576i 50hz through component. While when i launch it through Unleashx in PAL 576i 50hz i got black screen as always (working only with rgb).