Jack,
This will probably be the start of you thinking "what have I done by agreeing to help this person" but here goes.
I looked under "Adjustment of Height of Cut". I went to turn the black knob on either side, the ones you've put the red arrow towards. The left one, the knob just unscrewed right off the screw. The right one didn't budge. Are they what I'm supposed to be turning? If so, it seems like they've totally jammed up.
