Modded box has worked for years, 1 change and now no display

Thank you for reading about my problem, hope you can help.

I have a modded Xbox with an x3 chip. Everything has worked fine for several years. I was in the setting one day "I think it was the settings for the O/S" and I ended up changing a display setting. When I rebooted my box the display setting must have been wrong because now there is no picture. I have sound and I know that it loads the O/S because I know the menu sound when I move the joystick.
I have tried to FTP into the box and reload the contents of the "c" partition but that did not help.
I have tried booting directly to the mod chip by holding down the white button on the controller when I power it on, that did not work either.
Would the display setting that I changed be set on the HDD or the mod chip? How do I fix? Replace the HDD, reformat the HDD? Do I need a new do I need to start from scratch with a new unflashed chip?
Any suggestions would be helpful.

 

Also, I beleive that the O/S "dash board" that I am using is uleashx, it has been so long since I have done any of this so please forgive my stupidity.

 

I haven't modded a box for years, but it sounds like you just made a resolution change your TV can't handle, which has nothing to do with your mod chip. If I'm not mistaken, the instructions for resetting display are in the manual.

 

I haven't modded a box for years, but it sounds like you just made a resolution change your TV can't handle, which has nothing to do with your mod chip. If I'm not mistaken, the instructions for resetting display are in the manual.

 

I take it you are talking about an unleashx manual?