Hitachi SM0063 Service Manual page 55

(3) Measuring the Vs voltage Margin and deciding
the voltage
¤ Convert the signal of signal generator to the 100% Full
Red signal.
¤Ł Turn the voltage adjusting knob of Vs DC power supply
to the voltage -down direction and make the cell of
screen turned off.
¤Ø Turn the voltage adjusting knob of Vs DC power supply to
the voltage -up direction until the cell of screen turned on.
The first voltage, which make the cell of full screen
turned on, is named as Vsmin1 and record it.
¤Œ Turn the voltage adjusting knob of Vs DC power supply
to the voltage-up direction slowly until the cell of screen
turned off or over electric discharge.
The first voltage, which makes the cell of screen turned
off or over electric discharge, is named as Vsmax1 and
records it. (Only, Vs voltage variable passes over the
maximum 190V)
¤º Convert the signal of signal generator to the 100% Full
Green signal.
¤ Repeat the adjustment (2) item and name each voltage
as Vsmin2/Vsmax2 and record them.
¤ Convert the signal of signal generator to 100% Full Blue
signal.
¤ Repeat the adjustment (2) item and name each voltage
as Vsmin3/Vsmax3 and record them.
¤ Convert the signal of signal generator to 100% Full
White signal.
¤ Repeat the adjustment (2) item and name each voltage
as Vsmin4/Vsmax4 and record them.
¤æ Convert the signal of signal generator to 100% Full
Black signal.
¤ Repeat the adjustment (2) item and name each voltage
as Vsmin5/Vsmax5 and record them.
¤ At this time decided Vs voltage adds 6V to Max
value(Vsmin1~Vsmin5) and set up the voltage within the
set-up range(180V < Vs
other features.
¤ Turn the voltage adjusting knob of Vs DC power supply
make deciding the Vs voltage.
¤ı Adjust Vset-down wave form using setting up Vs voltage
like mentioned on the 4-3.
(4) Adjusting the final voltage wave form
Check the voltage wave form like the mentioned way on the 4-
3(How to adjust) and readjust the wave form when it is twisted.
(5) DC-DC Pack Voltage Set up Range
Vsetup : 185V ~ 225V
Vsc : 90V ~ 120V
-Vy : -60V ~ -80V
# 190V) in consideration of
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