SHARP 21GT20
Service Manual

PIF ADJUSTMENT CHECKING SHIPPING SETTING & CHECKING
NO POINT ADJUSTMENT CONDITION / PROCEDURE WAVEFORM OR OTHERS 1 Tuner IFT (1) Get tuner ready to receive the CH. E 9 (1) The following default data has been factory-set for the E2PROM. 10k 1n60 1000p ( PRESET ) signal, but with no signal input. Adjust the PLL data. Oscilloscope IF OUT

ITEMS DATA SETTING (2) Connect the sweep generator's output cable to 100k 75ohm LAST PROGRAM/CHANNEL 1 the tuner antenna. (RF SWEEP) FLASHBACK PROGARM/CH 1 (3) Adjust the sweep generator's to 80dBuV.
(4) Connect the response lead (use LOW Fig. 1 DIGIT 1 IMPEDANCE probe with wave detector ; see C-SYSTEM AUTO Fig.1) to the tuner's IF output terminal. S-SYSTEM *1 B/G (This terminal must have the probe alone
P C

E-9 CH

SKIP OFF connected ). AFC ON (5) Set the RF AGC to 0 6 V with no saturation COLOUR 0 (CENTER) BRIGHTNESS 0 (CENTER) Note : Be sure to keep the tuner cover in position
during this adjustment.

-1.5+/-0.8dB

VOLUME 1 with the waveform.
Fig. 2 as shown in Fig. 2.

CONTRAST 60 (MAX) (6) Adjust tuner IF coil to obtain the waveform

TINT 0 (CENTER) SHARPNESS 0 (CENTER) 2 RF-AGC (1) Receive "PAL COLOR BAR" signal. Signal Note : For the 50 ohm signal WHITE TEMP STANDARD TAKE OVER Strength: 57 ± 1dBµV (75 ohm open) strength gauge, when not

POINT (2) Connect the oscilloscope to TP201 (Tuner's using 50/75 impedance REMINDER TIMER In-active, ��:�� ADJUSTMENT AGC Terminal) as shown in Fig 3-1. adapter, signal strength is ON TIMER In-active, ��:�� (I2C BUS 52 ± 1dBµV (75 ohm OFF TIMER In-active, ��:�� CONTROL) open), instead of 57 ±
+ OSCILLOSCOPE �

LAST POWER POWER-ON 1dBµV (75 ohm open). LANGUAGE *1 THAI

TP201

0.1V

Precaution : The loss of using impedance adapter. BLUE BACK MUTE OFF +

BIAS BOX

7
� Bias Box : about 4.5V

HOTEL MODE OFF *1: PLEASE CHANGE IT BY REMOTE CONTROL
(3) Call "AG" mode in service mode. Adjust the "AG" bus data to obtain the Tuner output pin drop 0.1V below maximum voltage. (4) Change the antenna input signal to 63 ~ 67dBµV, and make sure there is no noise. (5) Turn up the input signal 90 ~ 95 dBµB to be sure that there is no cross modulation beat. Fig. 3-1

TV SET

20GT-20 21GT-20