Toshiba M-V19H01, Service Manual

Page: 122 / 166

Alignment and Adjustments (Electrical)
6-2
6-1-4 IC902 Replacement
1. When IC902 is replaced, all values are reset to
ÒInitialized MICOM Data,Ó so readjustment is
necessary.
2. Press the POWER button 10 seconds after
plug-in.
3. To enter the factory mode, refer to 5-1-2
(Factory Mode Adjustment).
6-1-5 PIF VCO Adjustment
1. Without connecting an antenna to the tuner,
feed a 45.75MHz signal to C104. Use a pattern
generator. Marked:
2. Adjust the VCO in the service mode; set IC200
Pin 44 (AFT) to 2.5V.
6-1-6 RF-AGC Adjustment
1. Input a PHILLIPS pattern (CH4).
2. Adjust the input signal so that it becomes
more than 60dB.
3. Enter AGC (Factory mode).
4. Adjust AGC so that IC200 Pin 5 is 4.57V.
Marked:
6-1-7 Sub-Contrast Adjustment
1. Input a gray scale pattern (CH4).
Use a pattern generator (PM5518).
2. Short D208 to disable the ABL feedback.
with an oscilloscope.
3. Using an oscilloscope, check IC200
Pin 19 (marked ) R-OUT .
4. Set the RC, GC, BC values to 0 (Factory
Mode). Check their initial values.
5. Adjust SCT to 2.4 ± 0.1Vp-p.
6. Remove the short across D208 in order to
restore the ABL feedback.
6-1-8 Sub-Tint Adjustment
1. Input a 7 color-bar pattern.
2. Using an oscilloscope, check IC200 Pin 21
(marked ) B-OUT.
In the factory mode, adjust STT until the 2th
and 3th peaks have equal heights.
6-1-9 Sub-Color Adjustment
1. Do the Sub-color adjustment AFTER the Sub-
Contrast and Sub-Tint adjustments.
2. Input a full color bar pattern.
Use a pattern generator (PM5518).
3. Check IC200 Pin 19 ( marked ) R-OUT
with an oscilloscope.
4. Ensure that RC, GC and BC data are Ò0Ó;
GG and BG should be 128.
5. In the factory mode, adjust SCR to
2.0 ± 0.1Vp-p (black and red levels).
Fig. 6-1 Sub-Contrast Adjustment