I was informed by the Norco delivery driver that the mechanical level gauge (LI105A) at the X-end dewar was not responding to changes in the LN2 level, i.e., it was stuck @ 205" WC.  I investigated and confirmed his observation.  In doing so, I also discovered that the valve connecting the High and Low lines to this gauge (V-7) was open.  This valve is normally closed and shorts out both the mechanical level gauge, as well as, the CDS level transducer which shares these lines and is connected in parallel to the mechanical gauge -> I will repair or replace the mechanical gauge on Tuesday.  For now, I closed V-7.  This should correct the "noisy" level signal that Chandra had noticed on CDS.