So we're all on the same page, I just walked over to the neighbor's and snapped a pic of his DK35 controls in that area.
As viewed in the picture, the far left is the mid-PTO control. If you have it, make sure it's in the off (down) position.
The orange steal rod that's bent 90° is your rear-diff-lock. Doesn't matter either way for hydraulics.
Your hydraulic float control is the round silver knob. Turn it counter-clockwise to increase 3-point-hitch implement drop speed. If too closed (clockwise), your implement won't come down.