So i've been update a buddies old modded xbox. No worries, everything going good. The xbox boots to the chip and a Xenium menu so took me awhile to navigate but figured it all out. I thought since my buddy isn't into any of the settings i'd set the chip to "quick boot" because I thought it would boot up every time, it's not like he needs the chip to be off to online game. Well, after I finished FTPing the last itme unto his xbox, I came back to start it up and check everything when...error 5. OK, the chip obviously isnt on. I placed the last hard drive in it and it boots to the original xbox menu not his old modded menu. So again, obviously the chip isnt turned on. I tried holding the start button to see f that would work but nothing. Does anyone know how to get this old chip to boot at startup?
I found it! Press and hold eject button. Sorry for the wasted thread but I was in a panic that I'd bricked my buddies xbox!
I had the exact same problem years ago and figured it out just like you did, but forgot to post about it. Good job!
Found a post on another site with more info about the Xenium Quickboot/Instant boot operations: If that's not enough help, I've attached a Xenium OS User Manual.