Vs, Va Voltage Adjustment - Hitachi 32HDT50 Service Manual

4. Vs, Va voltage adjustment

Adjustment part::VR51
-Preparation
1.Turn on the set and perform pre-heat run more than 1min.with snow noize screen.
2.Receive full black pattern (blanking level) signal (or Video No signal; in this case,
it will be autmatically turned off after a few seconds because of power save function).
3.Connect voltmeter leads to the Vs or Va and GND test points on power unit.
(Measurement error of voltmeter should be Less than 0.02V)
-Adjustment
(1)Turn VsADJ(VR51) to adjust Vs voltage to be within ± 0.1V of the value specified
in the label on the panel. *
(2)Turn VaADJ(VR51) to adjust Vs 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 value.Readjust if Itís outside the margin.
Label example*
<LOT>N6
Vs=80.0V Va=60.0V
V• =140.0V
-Remarks
*1. Permissive level of voltage in case sufficient time of heat-run performed.
Vs: within ± 0.45V, Va: within ± 0.55V
TITLE
2003ï 3ï 5
BACK TO ADJUSTMENTS
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Vx=60.0V
Label position (Reference)
32 inch screen: Upper left.
42 inch screen: Bottom left corner.
Power unit for 32 inch
PIN502• GND
PIN501• VS
VR51• VsADJ(on IC591 PWB)
PIN301 vA
VR51• VaADJ(on IC391 PWB)
Power unit for 42 inch
PIN502• GND
PIN501• VS
VR51• VsADJ(on IC591 PWB)
PIN301 vA
VR51• VaADJ(on IC391 PWB)
32
PT3-E/G AVC3-U