Service manual

20
20U-FS1
CU20FS1
20-1
20-2
ADJUSTMENT
ITEM
ADJUSTMENT
POSITION
CONTROL PRE-ADJUST
REQUIREMENT
CONTENT
INPUT
CONDITION
OUTPUT
ADJUSTMENT
PROCEDURE
(AT SELF ADJUSTMENT MODE)
1) GO INTO SERVICE MODE, BY SELECTING THE SERVICE DATA V10
2) PRESS THE R/C FOR AUTO PIF-VCO KEY, OSD APPEAR “OK” AT
SCREEN
3) IF APPEAR “NG” PLS REPEAT STEP2
4) AFTER “OK” CONDITION STEP DOWN ONE STEP.
(AT MANUAL ADJUSTMENT MODE)
1) GO INTO SERVICE MODE, BY SELECTING THE SERVICE DATA V10
2) ADJUST THE DATA UP/DOWN UNTIL IC801 PIN 2 VOLTAGE BECOME
AS SPECIFIED BELOW
PIF-VCO
V10 STEP RANGE 0~63
I
2
C CONTROL
OPTION SET UP, BUS SET UP
NO SIGNAL (RASTER) CONDITION
AC 120V
CONFIRMATION ON CRT DISPLAY (AUTO), IC801 PIN 2 VOLTAGE (MANUAL).
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
[CHECKING SPEC]
2.5 ± 0.5 V DC (CHECKING SPEC : 2.50 ± 1.5V)
(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