Service manual

20
20-1
20-2
20F630
CU20F630
ADJUSTMENT ITEM ADJUSTMENT POSITION CONTROL PRE-ADJUST REQUIREMENT CONTENT INPUT CONDITION OUTPUT
ADJUSTMENT PROCEDURE
RF-AGC
V08 STEP RANGE 0-127
I
2
C CONTROL
OPTION SET UP, BUS SET UP US10CH HALF COLOR BAR RF INPUT FIELD STRENGTH 56dBµV (FIX) TUNER AGC TERMINAL (TP 201) OR CRT DISPLAY CONFIRMATION
(AT SELF ADJUSTMENT MODE) 1. GO TO SERVICE MODE 2. GO TO SERVICE DATA V08, PRESS R/C TO OPEARATE AUTO-AGC
KEY AND CONFIRM THE OK DISPLAY ON THE SCREEN.
3. IF APPEAR NG PLS REPEAT STEP 2 AGAIN. (AT MANUAL ADJUSTMENT MODE) 1. ADJUST THE V08 BUS DATA UNTIL AGC TERMINAL VOLTAGE BE-
COME MAXIMUM, THEN DROP 0.1V BELOW MAXIMUM VOLTAGE.
2. CHANGE THE ANTENNA INPUT SIGNAL TO 63-67 dBµV, AND MAKE
SURE THERE IS NO NOISE
3. CHANGE THE ANTENNA INPUT SIGNAL TO 90-95 dBµV TO BE SURE
THAT THERE IS NO CROSS MODULATION BEAT.
[CHECKING SPEC] MAX - 0.1V dc
ADJUSTMENT ITEM ADJUSTMENT POSITION CONTROL PRE-ADJUST REQUIREMENT CONTENT INPUT CONDITION OUTPUT
ADJUSTMENT PROCEDURE
1) IN SERVICE MODE, SET V04&V11&V12&V13 TO 127; V14&V15 TO
64, GET IN Y-MUTE BY R/C AND SET V19 TO “1”, PICTURE APPEAR IN CUT-OFF CONDITION
2) ADJUST THE SCREEN SO THAT CUT-OFF LINE APPEAR IN LOW
BRIGHT, THEN JUDGE THAT WHETHER THE CUT-OFF LINE APPEAR IN RED OR GREEN OR BLUE COLOR, IN THIS CONDITION V11=R- CUTOFF, V12=G-CUTOFF, V13=B-CUTOFF, FIX THE DATA OF THE COLOR APPEAR IN CUTOFF LINE AND USE R/C TO ADJUST THE OTHER TWO CUT-OFF DATA SO THAT CUT-OFF LINE COLOR BE- COME WHITE.
3) TURN THE SCREEN VR OF FBT SO THAT CUT-OFF LINE JUST DIS-
APPEAR AND USE R/C TO SET V19 TO “0”, NEXT DISABLE THE Y- MUTE SO THAT PICTURE APPEAR IN NORMAL MODE.
SCREEN
V11,V12,V13 STEP RANGE 0-255
I
2
C CONTROL
OPTION SET UP, BUS SET UP WINDOW PATTERN OR US4CH LION HEAD 120V CONFIRMATION ON CRT DISPLAY
[VOLTAGE CONFIRMATION]