Service Adjustments - JVC AV-20N8(BK) Service Manual

AV-20N8

SERVICE ADJUSTMENTS

BEFORE STARTING SERVICE ADJUSTMENT
1. There are 2 ways for adjusting this TV: One is with the
REMOTE CONTROL UNIT and the other is the conventional
method using adjustment parts and components.
2. The setting (adjustment) using the REMOTE CONTROL
UNIT is made on the basis of the initial setting values. The
setting values which adjust the screen to the optimum con-
dition can be different from the initial setting values.
3. Make sure that connection is correctly made to AC power source.
4. Turn on the power of the TV and measuring instrument for warm-
ing up for at least 30 minutes before starting adjustment.
5. If the receive or input signal is not specified, use the most ap-
propriate signal for adjustment.
6. Never touch parts (such as variable resistors, transformers and
capacitors) not shown in the adjustment items of this service
adjustment.
MEASURING INSTRUMENT
AND FIXTURES
1. DC voltmeter (or Digital voltmeter)
2. Oscilloscope
3. Signal generator (Pattern generator)
[PAL / SECAM / NTSC]
4. Remote control unit
BASIC OPERATION IN SERVICE MENU
1. TOOL OF SERVICE MENU OPERATION
Operate the SERVICE MENU with the remote control unit.
2. SERVICE MENU ITEMS
With the SERVICE MENU, various settings (adjustments) can be made, and they are broadly classified in the following items of settings:
1. IF ............................. For entering/adjusting the setting values (adjustment values) of the IF circuit.
2. V/C ........................... For entering/adjusting the setting values (adjustment values) of the VIDEO/CHROMA and DEFLECTION cir-
3. VSM PRESET ......... For setting the values of STANDARD, SOFT and BRIGHT
10
cuits.
(VSM: video status memory)
7. Preparation for adjustment (presetting):
Unless otherwise specified in the adjustment items, preset the
following functions with the remote control unit.
Function
PICTURE MODE (VSM)
COLOUR/BRIGHT/CONT./SHARP
OFF TIMER
ECO SENSOR
BLUE BACK
PICTURE BOOSTER
ADJUSTMENT/CHECK ITEMS
Adjustment/Check item
B1 POWER SUPPLY Check
FOCUS Adjustment
IF CIRCUIT Adjustment
V/C (VIDEO/CHROMA) CIRCUIT Adjustment
DEFLECTION CIRCUIT Adjustment
VSM PRESET Adjustment
A2 SIF/DET Adjustment
PURITY, CONVERGENCE Adjustment
No. 56030
Setting value
BRIGHT
See "VSM Preset"
on page 23.
OFF
OFF
OFF
OFF
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