JVC AV-27320 Service Manual page 21

■ ADJUSTMENTS
B1 POWER SUPPLY
Measuring
Item
instrument
Check of DC Voltmeter 【 【 【 【 B1】 】 】 】
B1 POWER
SUPPLY
ADJUSTMENT OF VCO
Measuring
Item
instrument
MAIN VCO Signal
adjustment
gener ator
TUNER
HIGH LEVEL
REFERENCE LEVEL
LOW LEVEL
SYNC
ADJUSTMENT OF RF AGC
Measuring
Item
instrument
RF. AGC
adjustment
No . Setting item
S45 AGC ADJ
Test point Ad justment part
Connector
TP-91
TP-E(#)
Test point Ad justment part
10.VCO MAIN
CW TRANSF.(T111)
[MAIN PWB]
MAIN
GREEN
NO
Test point Ad justment part
S45 AGC ADJ
Variable Initial setting
range value
0 ～ 127
80
No. 51937
Description
1. Receive the blac k-and-white signal. (color off)
2. Connect the DC voltmeter to【B1】connector【1】pin (TP-91)
and TP-E(#) (B1 connector【3】pin).
3. Confirm that the voltage is DC134V±2V.
Description
" It mus t not adjust without signal
1. Select a receivable broadcast.
2. Push the FUNCTION ▼ / ▲ key, and selec t the 10.VCO
mode from the SERVICE MENU.
3. Push the FUNCTION /
4. Confirm that the color change from ｢HIGH LEVEL｣ to ｢LOW
LEVEL ｣ by CW TRANSF T111 at MAIN PWB, and check the
｢SYNC : YES｣.
5. Adjust until ｢REFFERENCE LEVEL｣ mark turns green.
And then confirm that the ｢SYNC : YES｣ again.
Description
1. Receive a black and white signal (color off).
2. Select S45 AGC ADJ of the V/C MODE.
3. Press the MUTING key and turn off c olor.
4. With the FUNCTION key to get the noise in the screen
picture (zero s ide of s etting value).
5. Press the FUNCTION
nois e dis appears from the screen ( at that time, not to increas e
the value too much).
6. Change to other channels and make sure that there Is no
irregularity.
7. Press the MUTING key and get color out.
AV-27320
AV-27330
AV-27S33
key, and s elect MAIN.
key several times and step when
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