softmodded my xbox by hotswapping xbox to pc and put UXE + Nkpatcher + Shadow C drive + Avalaunch files to xbox hd. At first, everything seemed to work fine, Avalaunch worked and I got ftp working well too. But when I tried to play (original) xbox games, Avalaunch showed that it was reading the disc, but then screen went black or gave error 21. Same thing with dvds.

I changed dvd-drive (from Thomson to another Thomson) and cleaned laser, same thing still. I hotswapped hd to pc, formatted it and used xboxhdm with option 'build new hd from a scratch' and files from Slayers aitoinstaller package. Now xbox opens with m$dashboard, and if I insert game or dvd, it gives message wich says that disc is dirty or damaged.

I don't have any ideas what to do and I have browsed tons of topics and guides but don't know what to do. Any ideas?

I would look at trying another DVD drive.

Well, I already tried another... you think both would be broken?

do apps and or games work when launched from the hard drive. never seen a bad dvdrom drive cause error 21. seems that something is not correct in the softmod due to the error 21 which in most cases is trying to launch a xbe file that is not signed.

I'll try that when I have time... But it doesn't anymore give error 21, now it just says that disc is dirty or scratched...