Signal source for adjusting TV.
 

I don't generally work on TVs, but I've always wondered, when adjusting one, should you use the best signal source available or the worst?

Like on a modern TV. Would you use a picture through the component video jacks, or would you use something through the RF connector?

I work on a lot of old sets, so I have to use RF.
On the newer sets, I use the component jacks, whenever possible.