Adjustment Instructions - LG CE-29Q46ET Service Manual

¡ Safety Precautions
1. It is safe to adjust after using insulating transformer between
the power supply line and chassis input to prevent the risk of
electric shock and protect the instrument.
2. Never disconnect leads while the TV receiver is on.
3. Don't short any portion of circuits while power is on.
4. The adjustment must be done by the correct appliances.
5. Unless otherwise noted, set the line voltage to 230Vac¡
10%, 50Hz.
5. The adjustment of TVshould be performed after warming up
for 15 minutes.
¡ Test Equipment required
1. RF signal generator (with pattern generator)
2. DC Power Supply
3. Multimeter (volt meter)
4. Oscilloscope
5. Color analyzer
V
IC102(KI7805)
R108
9V
R144
TP1(VCO)
Power-
Supply
5V
4.7 Kohm
S3
Q122
100 ohm
S2 JP3
Fig. 1 : Connection Diagram of Equipment for PIF Adjustment
¡ PIF (Picture Intermediate Frequency) Adjustment
Test Point : TP1
Adjust : L104
1) Connect the measuring equipment to the Main Board as
shown in Fig.1.
2) Set RF frequency and output level of RF SIGNAL
GENERATOR as shown Table 1.
3) Turn off S1 and S3 and on S2.
4) Adjust L104 so that the DC voltage may be 2.4¡ 0.05Vdc.
System Frequency
B/G,D/K/I,SECAM-L 38.9MHz
SECAM-LÕ 34.25MHz

ADJUSTMENT INSTRUCTIONS

Multimeter or Oscilloscope
1
IC101
TDA4470
0.01uF
22
7 JP1
38.9MHz
34.25MHz
L104
13
JP2
14
100 ohm
S1
VR122
Modulation
Output level
OFF
10mVp-p
OFF
10mVp-p
(Table 1)
¡ LÕ VCO Adjustment (For SECAM-LÕ MODEL)
Test Point
Adjust
1) Connect the measuring equipment to the Main Board as
shown in Fig.1.
2) Set RF frequency and output level of RF SIGNAL
GENERATOR as shown Table 1.
3) Turn on S1,S3 and off S2.
2) Adjust VR122 so that the DC Voltage may be 2.4¡ 0.05Vdc.
¡ RF AGC (Automatic Gain Control) Adjustment
Test Point
Adjust
1) Input PAL-B/G 05 CH.
2) Connect Multimeter to TP2(J15),AGC adjustment point.
3) Adjust VR121 until the voltage of Multimeter becomes
2.5¡ 0.1V.
¡ Screen Voltage Adjustment
Test Point
(B/G,D/K,I,L)
(SECAM-L')
Adjust
1) Tune the RF Modulator to receive a PAL or SECAM signal.
2) Press MIX button on remote controller for Service to get into
the Screen Adjust Mode.
3) Adhere the Color Analyzer on the White window of CPT
face.
4) Adjust Screen Volume of FBT so that the luminance of White
window is 12¡ 1 FL.
¡ Focus Adjustment
Test Point
Adjust
1) Tune the TV set to receive a digital pattern.
2) Adjust the upper Focus volume of FBT for the best focus of
vertical line B.
3) Adjust the lower Focus volume of FBT for the best focus of
area A.
4) Repeat above step 2) and 3) for the best overall focus.
Adjust
L104
VR122
- 9 -
: TP1
: VR122
: TP 2(J15)
: VR121
: CPT Face
: Screen Control of FBT
: Observing Display
: Focus control of FBT