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.
?????