Electrical Adjustment - JVC GR-AX640U Service Manual

3.1

ELECTRICAL ADJUSTMENT

3.1.1 PREPARATION
1. Precaution
This model does not contain adjustment controls (VR).
General deck system, camera system and monitor system
adjustment are not required. However, if MAIN board need
replacement, please use original E
Then adjustment are not required. And if parts such as the
following need replacement, special computerized adjust-
ment are required (Refer to sec. 3.1.1-4). Please contact to
JVC Service for detaile information.
• OP block
• E 2 PROM (IC105 of MAIN board)
In the event of malfunction with electrical circuits, trouble-
shooting with the aid of proper test instruments most be
done first, and then commence necessary repair, replace-
ment and adjustment, etc.
1. In case of wiring to chip test points for measurement, use
IC clips, etc. to avoid any stress.
2. Since connectors are fragile, carefully handle them in
disconnecting and connecting.
3. Shortcircuit between operation un it and DECK chassis.
2. Required test equipment
1. Color TV monitor.
2. AC power adapter
3. Oscilloscope (dual-trace type, observable 100 MHz or
higher frequency)
* It is recommended to use one observable 300 MHz or
higher frequency.
3-1
SECTION 3
ELECTRICAL ADJUSTMENT
2
PROM on to new board.
REW FF
STOP PLAY/PAUSE
MENU/
DISPLAY
PUSH
J
JLIP
SP/EP
EJECT
<Rear side>
Fig. 3-1-1 Connection for Service support system
4. Digital voltmeter
5. Frequency counter (with threshold level adjuster)
6. Personal computer
3. Required adjustment tools
For detsails of special jigs necessary for adjustment, refer to
page 1-2 and 1-3 of the Section 1.
4. Setup for E. VF section adjustment
(For GR-AX640U/UC)
Referring to "SEC. 1 DISASSEMBLY" and connect the E.VF
WIRE to CN12 of the MAIN board.
Note:
• This adjustment falls into a special adjustment that requires
a personal computer.
For details, refer to "3.1.1 Preparation".
(LY20374)
Bottom case assy
Parts NO.
LY20374
Adjustment ltem : 3.2
RS232C
COM Port
PC CABLE
QAM0099-002
SERIAL NO.
LABEL
SCREW
Service Support
System software
MENU
Personal Computer