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5. Tuner Adjustment:
Perform the following adjustment in case of replacing any adjustment element during the repair. Proceed with the following adjustments as
well as in the adjustment menu screen. If those adjustments are not completed on both sides, the required adjustment will not be registered
even thought the adjustment has been processed in the adjustment menu screen.
The components which will be affected due to the repair.
• VCO coil
• SIF coil
5-1. VCO ADJUSTMENT VCO(PIF) Adjustment / Video Carrier Frequency Free Running Adjustment
Input signal : RF-Color bar
Input level : 90dB
µ
V
Broadcast CH/fc=45.75MHz
Mode : TUNER
Test point : INPUT/TP-102 IF (TU101-PIN 11)
OUTPUT/TP-201 AFT (IC301-PIN 44)
Adjustment point : L205/P-IF
Measuring instrument : Oscilloscope
Pattern generator / Leader : LCG-404
1. Connect oscilloscope to TP-201.
2. Input specified level of RF signal to TP-102 and adjust L205 until TP-201 voltage becomes 2.8
±
0.3VDC.
5-2. SIF ADJUSTMENT Audio IF Modulation Adjustment
Input signal : AM/FM-SG RF OUT/4.5MHz - SIF
MOD OFF
90dB
µ
V
• Simple adjustment method receives normal broadcasting.
Mode : TUNER
Test point : INPUT / TP-202 : IC301-PIN 52
OUTPUT / TP-203 : IC301-PIN 54
Adjustment point : L201/S-IF
Measuring instrument : Oscilloscope
AM/FM-Signal generator
1. Connect oscilloscope to TP-203.
2. Input specified signal to TP-202 and adjust L201 until TP-203 voltage becomes 4.5
±
0.2VDC.
