Screen (G2); Picture Quality Adjustments; 2-6.1. Video Input - Sub Contrast Adjustment - Sony TRINITRON KV-27HS420 Service Manual

2-5. SCREEN (G2)

1. Input composite white fi eld into Video 1.
2. Set to service mode and adjust as follows:
(Fig. 1)
CXA2170P-2 PICO 1-> 0

2-6. PICTURE QUALITY ADJUSTMENTS

Preparation:
• Set PRO MODE (Reset).
1. Input signal (480i Composite):
• Color Bar Video 75 IRE (White) 75% modulation 7.5% Set-up.
• Color Bar RF 75 IRE (White) 75% modulation 7.5% Set-up.
2-6.1. VIDEO INPUT - SUB CONTRAST
ADJUSTMENT
Preparation:
• Input a Color Bar signal to VIDEO 1 (75 IRE 75%).
• Set picture mode: Single (Full) (PRO MODE Reset).
• Picture: Max
1. Set to Service Mode and adjust as follows:
2170P-2
NO. Name Control Function
01 RGBS R ON
2. Connect oscilloscope to Pin 1 of CN9001 (R.DRV) on the CH Board.
KV-27HS420/29DRC420/30HS420/32HS420/34HS420/36HS420
Opeartion Procedure
1) In Full mode, apply changes in Fig. 1
2) Mount G2 adjustment jig. Adjust Cathode
voltage if the standard is not met. Standard
varies by CRT size.
3) Adjust G2 by Flyback transformer (T8001).
4) Return data changes in 1) to original condition.
Avg. Data
4
KV-27HS420/29DRC420/30HS420/32HS420/34HS420/36HS420
Standards
170 +/- 5 (V )
DC
175 +/- 5 (V )
DC
3. Adjust contrast according to the service mode item: SPIO.
2103-1
NO. Name Control Function
02 SCON SUB-CONT
white
VR1
(27HS/29HS) = 1.84 ± 0.05 Vpp
(30HS) = 1.92 ± 0.05 Vpp
(32HS) = 1.92 ± 0.05 Vpp
(34HS) = 1.92 ± 0.05 Vpp
(36HS) = 2.00 ± 0.05 Vpp
4. Press MUTING then ENTER to write into memory.
Notes
29RSN, 32RVEN
34RSN, 36RV2, 38RSN
black
VR2
GND
VR
17