Vco Adjustment - Emerson EWT19S2 Service Manual

4. H f Adjustment
o
Purpose: To get correct horizontal frequency.
Symptom of Misadjustment: . If H f
correct, skew distortion will appear on the screen.
Test Point Adj. Point
CH o / p button
R583
["H-ADJ"] MODE
Tape M. EQ.
Frequency
---
Counter
Note: R583 --- Main CBA
Use Service remote control unit.
1. Connect Frequency Counter to R583 and ground.
2. Set the unit to the VIDEO mode which is located be-
fore CH2 and no input is necessary. Enter the Ser-
vice mode. (See Page 5-1)
3. Operate the unit for at least 20 minutes.
4. Press "2" button on the Service remote control unit
and select H-ADJ Mode. (By pressing "2" button the
display will change from TV AGC to H-ADJ.)
5. Press "CH o / p" button on the Service remote
control unit so that the display will change "0" ~ "7."
At this moment, choose the display from "0" ~ "7"
when the Frequency Counter is closest to 15.734
kHz±300Hz.
6. Turn the power off and on again, using the main
power button on the TV unit.

5. VCO Adjustment

Purpose: To operate VCO correctly.
Symptom of Misadjustment: VCO does not work
correctly and/or synchronization is faulty.
Note: Use Service remote control unit.
1. Disconnect the RF input and set the unit to Channel 4.
2. Enter the Service mode. (See Page 5-1)
3. Press "3" button on the Service remote control
unit. The Auto VCO adjustment is started.
4. If the display color is changed from red to green,
this adjustment is done.
5. Turn the power off and on again, using the main
power button on the TV unit.
adjustment is in
0
Mode Input
--- ---
Spec.
15.734kHz±300Hz
5-3
6. AGC Adjustment
Purpose: Set AGC (Auto Gain Control) Level.
Symptom of Misadjustment: AGC does not syn-
chronize correctly when RF input level is too weak and
picture distortion may occur if it is too strong.
Test Point Adj. Point
CH o / p
TP301
buttons
Tape M. EQ.
Pattern
--- Generator DC
Volt Meter
Notes: TP301 --- Main CBA
Use Service remote control unit.
1. Enter the Service mode. (See Page 5-1) Then
press number "2" button on the Service remote
control unit.
2. Receive the Color Bar signal for channel 4
(67.25MHz). (RF Input Level: 60dBµV)
3. Press "CH o / p" buttons so that the voltage of
TP301 becomes +2.5±0.1V DC, if the tuner is
used TEDH9-309A. (Tuner type number)
4. Press "CH o / p" buttons so that the voltage of
TP301 becomes +2.8±0.1V DC, if the tuner is
used B8095AP. (Tuner type number)
5. Press "CH o / p" buttons so that the voltage of
TP301 becomes +2.7±0.1V DC, if the tuner is
used ENV56DB3G3. (Tuner type number)
6. Turn the power off and on again, using the main
power button on the TV unit.
7. Black Level Adjustment
Purpose: Set Black (Sub-bright) Level
Symptom of Misadjustment: If Sub-brightness is
incorrect, proper brightness cannot be obtained by
adjusting the Brightness Control.
Note: TP300 (GND), D316 (Cathode) --- MAIN CBA
1. Enter the Service mode. (See page 5-1.)
2. Press "MENU" button on the Service remote con-
trol unit and select "BRT" mode. (Display changes
"BRT," "CNT," "CLR" and "TNT" cyclically when
MENU button is pressed.)
3. Press "CH o / p" buttons on the Service remote
control unit so that the value of "BRT" becomes
128.
4. Turn the power off and on again, using the main
power button on the TV unit.
Mode Input
Color Bar
RF 67.25MHz
60dBµV
Spec.
+2.5±0.1VDC or
+2.8±0.1VDC or
+2.7±0.1VDC
by Tuner Type.
L6118EA