when the drill is  down, and the  openers are to-depth,   what are you seeing for  rod stick-up  on the down pressure springs?    
I too have a bare yetter cart with a 20'  5400  
I keep my  pressure adjuster  to max all the time,   but in  harder soil,  I'll  adjust the  2    front  drive tires so it  puts the planter closer to the ground-  which increases  down pressure immensely.       Which would be way too much  pressure for worked ground.
I like to see  about  4-5 inches of that rod sticking up from the spring holders in no-till  ground.   

getting it  set on one tractor won't mean it's  good for anything hitched to it.   a  change in  4-5 inches of  tractor tongue height can change the down pressure  big time.  
I also have  several rows  where the packer wheel  (depth guage)  is  different  according to  where the  tractor wheel track is.  
Most are in the 2nd notch from the rear,  some are in the 3rd.

Check to see if your  down pressure adjuster brackets  haven't  sheared a mounting bolt near the  jack screw. 
How fast are you pulling it?   no till needs to slow down a little.. give it time to cut-in.