Electrical Adjustment; Preparation - JVC GR-FXM270A 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 and
MONITOR board need replacement, please use original
2
E PROM on to new board. Then adjustment are not required.
And if parts such as the following need replacement, special
computerized adjustment are required (Refer to sec. 3.1.1-
4). Please contact to JVC Service for detaile information.
• OP block
2
• E PROM (IC104 of MAIN board)
• MONITOR
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.
4. Digital voltmeter
5. Connection for Service support system
3-1
SECTION 3
ELECTRICAL ADJUSTMENT
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
Referring to "SEC. 1 DISASSEMBLY" and connect the E.VF
WIRE to CN12 of the MAIN board.
Note:
PC CABLE
Fig. 3-1-1 Connection for Service support system
(LY20686)
Bottom case assy
Parts No.
LY20686
Adjustment ltem : 3.3
• This adjustmentalls into a special adjustment that requires
a personal computer.
For details, refer to "3.1.1 Preparation".
RS232C
COM Port
Personal Computer
Serial No.
label
Screw
Service Support
System software
MENU