QUOTE(RustAngel @ Jan 18 2005, 11:40 PM)
A fix for people whose xboxes throw back error 21 or boot and re-boot in an endless loop following an NTSC-j/resolution change error (you will need a copy of the Enigmah switchdisc or Slayer's EvoX bootdisc and a modchipped xbox - will not work for softmods AFAIK):
I figured out a way to fix my xbox (softmodded) after messing with resolution/widescreen setting in XBMP. If you upgraded the hard drive and still have the original it is the easiest, but it should also work if anyone you know has a modded (soft or not) xbox and will let you open it up and hot-swap their hard drive and yours.
1st - Make sure you have a working copy of Enigmah Videomode Switchdisc on disc or installed on the working modded Xbox. Remove the hard drive from you not working Xbox and have ready. Remove the cover of the working Xbox and leave off.
2nd - Boot the working Xbox to modded dash - ie Evox - then load the Enigmah Videomode Switchdisc Program. It should display your normal setting either NTSC or PAL. DON'T CHANGE ANYTHING YET
3rd - Now remove the power cable to the 'working' hard drive, then remove the IDE cable from the 'working' hard drive. Next attach the IDE cable to the 'not working' hard drive, then attach the power cable.
Last - I would press A once, then B once and make sure that Enigmah shows a change, then choose the mode you need (A = PAL, B=NTSC. Now power off the Xbox. Disconnect the 'not working' hard drive and try in your Xbox.
This worked for me on my Softmodded Xbox. I had my orginal softmodded stock hard drive so I removed my larger hard drive and was able to boot fine with my stock drive, ran Enigmah on my stock drive, hot-swapped to my not working larger drive, chose NTSC and shut off my Xbox. When I rebooted my larger drive was working fine again. Hope this helps someone else who had this problem with a softmod and no access to a Modchip.