First, please forgive my ignorance on this issues. I've been scouring the net for days on this topic, and only just now located these forums. The methods I used were probably not the best, because I had not found this place yet!
I have an old XBox (got it at launch) and decided to softmod it finally. My Dash version was correct for the SID installer (used Halo 2 a long time ago to update it!). I grabbed the SID 5.10 pack and the Splinter Cell savegame for the exploit method, and transferred these files to a Microsoft standard memory unit using an XBox controller --> USB cable and Action Replay. The transfers went fine. Afterward, I transferred these files to my XBox HDD, and launched Splinter Cell. After loading the savegame, I was able to get into the SID installer without issue.
Once there, I backed up everything I could (Eeprom, C drive, MS), and then proceeded to the Dual Boot installations. I chose the Hacked Dash / MS Dash install option, and choose the RGB option (as I was outputting over RGB cable to a VGA monitor). The installation went without error.
When the installation finished, I was greeted with a message about how I needed to "Shut down the system, remove any DVD, then restart the system", or something to that effect. I may have botched things here - I pushed the eject button to remove Splinter Cell from the tray. Immediately after ejecting halfway, the tray retracted and the system rebooted itself.
After this, I was only able to load a black screen. Powering off the machine and then using the power button to turn it on gives me the blank screen again. Using the eject button to power on the XBox lets me boot to the retail dashboard as normal, and operation seems fine there.
I thought I would re-use the savegame exploit to get back to the softmod installer, run an uninstallation, and try again. Unfortunately, every time I try to launch the Splinter Cell Exploit, the SID installer will not run. Instead, the game loads a level, but doesn't output video. I get a blank screen, but I can still hear and control Splinter Cell. Attempting the savegame exploit with Mech Assault instead of Splinter Cell didn't fair much better - it just reboots the game when trying to load the exploit, and the colors are messed up.
Could outputting over VGA be in any way an issue here? I'm not sure.
At this point I'm wondering (A) where I screwed things up, and (B ) how and if it's possible to recover and try to softmod again. Any input would be greatly appreciated. Again, sorry for the noob topic, but thanks very much for reading!