Power Supply Vs, Va Voltage Adjustment - Hitachi 42HDX62A/DW1-UA Service Manual

4. Vs, Va voltage adjustment
Item Power Unit Vs, Va Adjustment
Adjustment Preparations
(1) Turn on the set and perform
pre-heat run more than 1 min
on burn-in screen.
(2) Receive full black pattern signal
(or video silence signal; but the
power will be automatically turned
off after a few seconds by power
save function.)
(3) Connect voltmeter (which has an
error within 0.02V or less) leads
to Vs (or Va) and GND test points
of the power unit.
Never touch this VR ! (PFC)
(This is already adjusted.)
BACK TO ADJUSTMENTS
Adjustment Procedures
(1) Turn Vs ADJ to adjust Vs voltage
to be within 0.1V of the value
specified in the label on the panel.
(2) Turn Va ADJ to adjust Va voltage
to be within 0.2V of the value
specified in the label on the panel.
(3) Reconfirm that Vs voltage remains
within 0.1V of the specified value.
Readjust if it's outside of the
Label example
<LOT>N6
Vs= 80.0V Va=60.0V
V =140.0V Vx=60.0V
Never touch this VR ! (OLP)
(This is already adjusted.)
Adjustment driver insert into this
hole to adjust Vs VR R1540.
31
Adj. point Refer to following
Remarks
Permissive level of voltage in
sufficient time of heat-run
performed is:
Vs: within 0.45V
Va: within 0.55V
margin.
Label position (Reference)
: Upper left
If it's hard to read the voltage
value because of the wiring
positions, write it down by a
marker at visible place in
advance.
CN64 Vs/Va
pin: Va
pin: Vs
pin: GND
R1573 Va ADJ. VR
R1540 Vs ADJ. VR
(UNDER the FIN)
R1540 Vs potenciometer
DW1U
Test pins