Sony TRINITRON GDM-1601 Service Manual page 35

2-13_ White Balance Adjustment
D
0
0 0
D
o
RV403
RV402 RV401
RV405 RV404
S1
1
Fig_ 2-13-1 A board (view from rear)
Conditions: I. Age the set longer than 30min.
2. Face east or west.
3. After convergence, landing and white bal-
ance rough adjustment have been done.
4. Use the Minolta TV color analyzer II,
calibrated by Sony spectrometer.
(I) Set the senser of TV color analyzer to the screen
center.
(2) Input gray scale signal with 5% set up.
(3) Set Cont.VR to maximum.
(4) Gradually change the G2 (SCREEN) VR and
stop at the point where the pedestal level is
just extinguished (check that set up level lights
faintly).
(5) Set Cont.VR to minimum.
(6) Input full white signals and adjust the G.BKG
(RV404) and B.BKG (RV405) for dark level
white balance.
(7) Return Cont.VR to its previous maximum con-
dition.
(8) Adjust the G.DRV (RV402) and B.DRV (RV403)
for the high light white balance.
(9) Change signals to gray scale then check the
pedestal level is disappeared and set up level is
appeared.
(J 0) Repeat item (4) through (9) to get good white
balance both high light and dark level.
*
note
The color temperature is set to 9300 degrees K
+8 MPCD as represented by X and Y CIE cordinates
of X
=
0.283 ±0.03, Y
=
0.298 ±0.03.
4-9
3. SAFETY RELATED ADJUSTMENTS
The following adjustments and operational checks must
be made to ensure safety from X ray emission from the
set when D Board or H.V Assembly or Power Block are
changed or repaired.
I) Checking Test Point Voltage
Check the voltages -on the test points (TP30 I, 302
and 304) whether or not they meet the standard
values if the parts marked
~
are changed. Change
the parts marked H if the standard is not met.
Changed
Check Point
Adjust
Parts / ~) Part/H)
0302 TP301
=
OC 32.00
~lgg
V 0302
0301, R305,
TP302
=
OC 9.60 ±0.1O V
R345
R314, R345
0302, RV301, When RV301 is turned
R31l, R312,
and
TP304' S voltage R312
R313
value becomes maximum,
the value must be less
than 9.45V
*
Conditions. Input voltage: 100 to 120 V AC.
+B voltage: 146.0 VDC
(GDM-1602: 121.0 VDC)
Input signal: White dot
(white on black)
CONT: Where a dot can be seen
vaguely.
2) Replacing Power Block Assy and Checking After Part
Replacement
Check that the +B MAX voltage value is within the
standard and that OVP circuit operation is normal if
the power block assy or a part in the power block
assy (G board) is replaced.
(l) Checking +B max voltage
Condition. Input voltage: 130 VAC
Input signal: White hatch on black
CONT: Minimum
The voltage on pin
CD
of connector D-1 should
be below 146.0VDC (GDM-1602: 121.0VDC).
(2) Checking OVP circuit operation
Check that the OVP circuit operates and taht
pictures disappear if 161.50 VDC (GDM-1602:
134.00 VDC) is applied to the +B line from the
outside.
3) Checking After Replacing D Board for FBT in HV
Block
Check that pin
CD
of connector D-3 on D board has
a voltage of + 15.0 ±4.0 V if the D board for the FBT
in the HV block is replaced.