DBX 242 EQ High Frequency Roll-off Problem

Im wondering if anyone knows how the DBX242 works?    When i run a signal through it it sounds like its rolled off.  The HF shelf works.  If i bypass the 242 with all the settings at 0 there is a drastic change in the treble.  All the other bands sound like they are fine.  Ive looked at the limited available videos on the net and dont think this is how it is supposed to sound out of the box.

I dont have schematics.  Dbx doesnt post them. 

Wanted to get an idea where to start the troubleshooting.

Thanks for any help!