NEC PX-50XM4 series Service Manual page 254

(5) Lighting in green, and then in red (Alarm of power voltage error)
Unlike [lighting in red] in the STANDBY mode, [lighting in green] continues for about 30 seconds without any
output of images and audio signals. Since then, the mode turns into [lighting in red].
Lighting in red
Make an OFF → ON setting
twice for the main power
supply in order to reset the
alarming condition.
Is the LED lit in red after it
has been lit in green for about
30 seconds?
YES
When the main power supply is turned on in
the state that the AD, PD, and PH
connectors are disconnected, are there the
Vs (170Vdc) and Vd (60Vdc) outputs at Pins
to Pins
-  - 
a 5Vdc output at Pins -
connector? In this case, is the LED not
turned in red after it has been lit in green for
about 30 seconds? At that time, however, no
images are generated.
NO
When the main power supply is turned on in
the state that the PA and PV connectors are
disconnected from one after another, is
there a 12Vdc output at Pins -
connector or the 12Vdc and 6Vdc outputs at
Pins and of the PV connector? In
 - 
this case, is the LED not turned in red after it
has been lit in green for about 30 seconds?
NO
Is there an output of 3.3Vdc available at Pins
 ~  and 2.5Vdc at Pins
state that the PA and PV connectors are
returned to the former state, the main power
is turned ON, and the PN connector is
disconnected? In this case, however, this
check must be finished in 30 seconds.
Otherwise, there will be power tripping on
account of an alarm.
YES
The MAIN PWB is fault.
NO
of the PD connector and
of the PH

of the PA

 ~  in the
(Caution) How to reset the alarming condition The
alarming condition can be reset when an
OFF→ ON setting is repeated twice for the
main power supply in the state that the
LED is lit in red. The interval between the
first and second settings is not particularly
specified.
Normal
YES
The PDP is fault.
(Caution) The voltage values of Vd and Vs
YES
The MAIN PWB or the
AUDIO PWB is fault.
NO
The Power unit or the
PN connector is fault.
5-7
CONFIDENTIAL
To the separate PDP
service manual
can differ according to the PDP.
The method of checking these
voltage values is obtainable from
[2. Adjustment of the power unit]
in the method of adjustment.