I've been trying to softmod an old Xbox for the last few weeks. As background, I tried 8 different USB sticks - non worked. So I got a second hand Action Replay. I've tried NDURE, SIDs 4, 4.5, 5 and 5.1, all with Action REplay 1.3 & 1.4 and MaxDrive software, with 2 different original Splinter Cells Disks on 2 different machines - a lot of permutations!! Both have 5690 dash. I've searched high and low and read every tutorial I can. The closest I got was after hitting "Check Points" the screen went black and the LED went Orange. From what I finally found via searching, that meant the AR card was corrupting the saves. I doubled checked by copying a stock save to the xbox and back - worked just fine.
So today I tried moving them from the PC one at a time - hey presto, I got a bit further. But when I hit "check points", instead of freezing, I'm getting the ERROR 21 screen. (with SID 5.1 via Max - all of the others just hung at the check point screen.) I can't seem to find anyone in the same predicament - Error 21 seems to happen AFTER modding, but I can't even get that far! When I restart - it goes to the normal MS Dash with no game and games run normally.
Hotswapping is going to be a last resort - I'll have to piece together a PC as I primarily use a laptop.