Changed a setting and need a video/step by step tutorial please

As the title suggests I need help with my xbox. I am one of those people who doesn't own a newer tv and by that I mean I'm using a round screen/box tv which does not have HDMI USB capability so I had to purchase a HDMI cnverter to use my xbox one. Now the problem isn't with my converter but more with a setting I changed on my xbox. I was annoyed with the fact that my screen wouldn't fit properly and changed the wrong setting on my xbox one causing nothing to display on the tv and I also shut down the xbox instead of pressing A+^+A vise versa. I just simply need either an exact word for word tutorial or preferably a video showing that I have to press X button X amount of times in this order. All I remember is that the setting is in video output and it isn't the resolution option 1080p etc but some other option right under it or something like that. I would greatly appreciate it if someone could provide the needed information because my only other option would be to send it back to microsoft since I can't even use the Xbox one offline diagnostics tool to try and reset settings (That is the conclusion that microsoft customer support decided to think was the only option but kept forgetting I cant see my screen so I can't see what is needed.)

By any chance does your computer have a separate monitor?

@Jaysonguy: I don't own 2 monitors and am currently on a laptop but I have some old dell monitor nearby which I just checked and does not have HDMI or at least not the same plug as the xbox one.

I don't know what country you're in but I do have a longshot.

Go to an electronics store. Something like a Best Buy, call the manager and ask if they can help you. A good manager will let you bring it in and hook it up to one of the display models. It's a good faith gesture that gets them good will (hoping you'll buy things from them when you're able)

No friends with an HD set?

Not sure how to can afford an xbox one but not have a hd tv in 2016!

@Jaysonguy:I don't know if I'll be able to go to an electronic store any time soon but I'll have to keep that in mind and all my friends (if you can call them that) are all online friends.

Really you'd be better off just buying a modern tv. Surely you can get a small display, either new or used for very little money. Probably used for the cost of a new game if you go to a second hand shop or maybe even a pawn shop, might get lucky and find one at a charity/thrift store.

You wouldn't have this issue plus you'd be able to see the games like they are intended to. Honestly gaming on a non HD TV with an XB1 kinda defeats the purpose of having a modern console anyway, thats why they all come with HDMI cables.

@capri2s: Oh I definantly plan on getting a newer TV soon. Just I currently don't have the funds and I was gifted the xbox one.

@hahadead7777: ohh I see, that's a bit of a different story entirely. Sorry I can't help. Good luck.