Agilent 4294A Precision Impeda

Situation:
      The LCD (P/N 2090-0574) used for the 4294A was obsolete and replaced with a new LCD which employs a
long-life backlight lamp. It is assumed that lifetime of old LCD’s backlight will end in 2004 and after. So, when the
backlight lamp of the old LCD is faulty (burned-out), replace only the lamp (P/N 5188-1364) with a new one, not
whole LCD unit. This is because the old LCD (2090-0574) unit was no longer supplied and we cannot have enough
number of it to replace all defective LCD units.
 
When the LCD itself is faulty, replace the faulty LCD with the old type LCD (use P/N 5185-3731 in place of the
obsolete P/N 2090-0574) or new LCD (P/N 2090-0361) depending on the instrument serial number. (The LCD
contains the backlight lamp, but the backlight lamp in the new LCD can not be replaced independently)
 
      The new LCD has different assembly size from old one and new replacement parts for the new LCD have been
set up.