B Board Adjustment - Sony FDL-PT22/JE Service Manual

3-3. B BOARD ADJUSTMENT

- B BOARD - (COMPONENT SIDE)
RV301
RV402
GRADATION ADJUSTMENT
(1) Input a 10-step staircase signal from the test signal generator.
(2) Connect an oscilloscope probe between JL83 (G) and JL67 (D.
GND) and observe the waveform.
(3) The contrast should change when RV402 is turned.
(4) Connect the oscilloscope prove between JL84 (AUTO CB) and
JL67 (D. GND), and observe the waveform. Adjust RV402 so
that voltage A is 2.2 0.2V
(5) Check that the waveform between JL84 and JL67 is as shown
in Fig.3-4.
(6) Check to see that the phases C and D are within the range speci-
fied ( ).
JL83
0 IRE
C
JL84
A = 2.2
Fig.3-4
100 IRE
Picture contrast
is varies.
D
0.2V
– 10 –
HUE ADJUSTMENT
(1) Receive a color bar.
(2) Insert an oscilloscope between JL81 (B) and JL67 (D.GND).
(3) Arrange RV301 as shown in Fig.3-5.
Fig.3-5