Viper GC Extreme is not booting backups

[andzlay]

Hey folks

I have finally installed the viper gc extreme in one of my cubes and unfortunately it is not booting any backups...
The backups I tried are working in other cubes with normal viper or xeno 2.0 and original games are working on the extreme-cube too!
I select "direct disc boot" in cobra 2.1, then the gamecube logo appears and turns and acts like there's no disc inserted. It's not possible to use cobra filemanager to view the data on the disc...
I tried to use the other cobra 2.1 bios files with GCOS drivecode but I have the same problem with them

Any ideas? My next thought is to try other cobra versions (2.0)

[emu_kidid]

Sounds 100% like the laser is almost dead in that cube if you can't even view the files on the disc Check the pot value..

[andzlay]

I also got some other drives I can try Thanks