Sharp 20GT-15, Руководство по обслуживанию

Страница: 9 / 40

7
20GT-15
SHIPPING SETTING & CHECKING
(1)
The f
ollo
wing def
ault data has been f
actor
y-set f
or the E2PR
OM.
ITEMS
D
A
T
A
SETTING
LAST PR
OGRAM/CHANNEL
1
FLASHBA
CK PR
OGARM/CH
1
DIGIT
1
C-SYSTEM
A
U
T
O
S-SYSTEM
*1
B/G
SKIP
OFF
AFC
ON
V
OLUME
1
CONTRAST
60 (MAX)
COLOUR
0 (CENTER)
BRIGHTNESS
0 (CENTER)
TINT
0 (CENTER)
SHARPNESS
0 (CENTER)
WHITE TEMP
ST
AND
ARD
REMINDER TIMER
In-activ
e
,
”—:—”
ON TIMER
In-activ
e
,
”—:—”
OFF TIMER
In-activ
e
,
”—:—”
LAST PO
WER
PO
WER-ON
LANGU
A
G
E
*1
THAI
BLUE BA
CK MUTE
OFF
HO
TEL MODE
OFF
*1:
PLEASE CHANGE IT BY REMO
TE CONTR
OL
PIF ADJUSTMENT CHECKING
ADJUSTMENT POINT
ADJUSTMENT CONDITION / PROCEDURE
WAVEFORM OR OTHERS
1
Fig. 1 Fig. 2
Fig. 3-1
OSCILLOSCOPE
BIAS BOX
TV SET
Bias Box : about 4.5V
TP201
0.1V
E-9 CH
P C
-1.5+/-0.8dB
10k
100k
1n60
75ohm
IF OUT
1000p
Oscilloscope
NO
Tuner IFT ( PRESET )
(1)
Get the tuner ready to receive the CH. E - 9 signal, but with no signal input. Adjust the PLL data.
(2)
Connect the sweep generator's output cable to the tuner antenna. (RF SWEEP)
(3)
Adjust the sweep generator's to 80dBuV.
(4)
Connect the response lead (use LOW IMPEDANCE probe with wave detector ; see Fig.1) to the tuner's IF output terminal. (This terminal must have the probe alone connected ).
(5)
Set the RF AGC to 0 - 6 V with no saturation with the waveform.
(6)
Adjust the tuner IF coil to obtain the waveform as shown in Fig. 2.
Note :
Be sure to keep the tuner cover in position during this adjustment.
2
RF-AGC TAKE OVER POINT ADJUSTMENT (I2C BUS CONTROL)
(1)
Receive "PAL COLOR BAR" signal. Signal Strength: 57
±
1dB
µ
V (75 ohm open)
(2)
Connect the oscilloscope to TP201 (Tuner's AGC Terminal) as shown in Fig 3-1.
(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 ~ 67dB
µ
V, and make sure there is no noise.
(5)
Turn up the input signal to 90 ~ 95 dB
µ
B to be
sure that there is no cross modulation beat.
Note :
For the 50 ohm signal strength gauge, when not using 50/75 impedance adapter, signal strength is 52
±
1dB
µ
V (75 ohm
open), instead of 57
±
1dB
µ
V (75 ohm open).
Precaution :
The loss of using impedance adapter.
+ – + –