Commercial Fixed Wing
Air Traffic Control Fully Certified
Air Traffic Control Radar 29.8
Other / Unknown
ATC Issue All Types
General None Reported / Taken
ATC Equipment / Nav Facility / Buildings
I was working the EMPYR arrival scope for LGA.  I had 1 VFR Eastbound at 9;500 FT and about 7 or 8 IFR arrivals; some on the STAR and some on vectors.  I was using EWR RADAR which is typical for this position and provides the best coverage to the southwest; which is where the initial arrival fixes are located.  I suddenly lost all MODE C altitude readouts; both on my targets and on all other targets on the scope.  After notifying the CIC and waiting a few minutes to see if the condition would self correct; I was forced to switch to JFK RADAR.  The targets displayed correctly; however we cannot take hand offs as early as on the EWR RADAR.  Recommend to analyze the technical data to see what happened and provide some kind of solution/redundancy.
N90 Controller noted a sudden failure of Mode-C information while utilizing the EWR RADAR site; forced to switch to JFK RADAR; the reporter noted this RADAR site limits hand off operations.