3-1
SECTION 3
ELECTRICAL ADJUSTMENT
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 E
2 PROM on to new board. Then adjustment are not required.
And if parts such as the following need replacement, spe-
cial computerized adjustment are required (Refer to sec.
3.1.1- 4). Please contact to JVC Service for detaile informa-
tion.
• OP block
• EEP ROM (IC102 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 dis-
connecting 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. Frequency counter (with threshold level adjuster)
6. Personal computer
Fig. 3-1-1 Connection for Service support system
Note:
•
This adjustmentalls into a special adjustment that requires
a personal computer. For details, refer to “3.1.1 Prepara-
tion”.
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.
Serial No. label
Bottom case assy
Parts No.
Adjustment ltem : 3.2
LY20701
Screw
(LY20701)
5. Connection for Service support system
Service Support System
RS232C
COM Port
PC CABLE
Personal Computer
MENU
Cover(JIG)
Jig connector cable
Extention connector
CN25
RED
to 10 pin
( RXD )
WHITE
BLACK
to 28 pin
( TXD )
to 8 or 5 or 4 pin
( GND )
JIG CONNECTOR COMMUNICATION CABLE
For supplying the power through the coupler by removing
the cover (for jig), use this extension connector double
for connecting the jig connector cable.
NOTE:
