[DW7491 table saw not maintaining blade height]

Finally got my blade to lower and now it will not raise.  Very frustrating.  Is there an adjustment screw that needs to be loosened?

 

[DW7491 table saw not maintaining blade height]

I have not had the blade height wander but I am having a related issue.  The blade height on my DWE7491 is stuck at the maximum height.  This is a saw that only has about 60 minutes of use so corrosion should not be the problem.  Nevertheless, I sprayed WD40 on the two shafts and was able to get a little movement up and down.  I don't want to put too much leverage and was hoping someone has had a similar issue.  This happened after I was ripping some rock maple which is surprisingly dense.  The saw did not overheat or bind.