3-1
Service support s
YTU94057-41
RS232C
port
PC cable
QAM0099-002
Personal computer
MENU
JLIP
J
SECTION 3
ELECTRICAL ADJUSTMENT
3
.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, special
computerized adjustment are required (Refer to sec. 3.1.1-
3). Please contact to JVC Service for detaile information.
• OP block
• E
2
PROM (IC1003 of MAIN board)
• MONITOR
• E
2
PROM (IC7603 of MONITOR board)
Note:
For B/W VF assembly adjustment is needed VRs.
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)
Note:
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
3. Required adjustment tools
For detsails of special jigs necessary for adjustment, refer to
page 1-2 and 1-3 of the Section 1.
3.2 E. VF SECTION ADJUSTMENT (B/W VF ONLY)
Referring to “SEC. 1 DISASSEMBLY” and connect the E.VF
FPC to CN104 of the MAIN board.
Note:
This adjustment can be carried out in the condition that
only the exterior part (EYE PIECE ASSY, VF CASE
[U]) is removed from the viewfinder.
With meticulous care not to damage any part, remove
the VF case (U) and expose the VF board assembly by
taking it out and carry out this adjustment using the
patch cord for connection.
VF CASE(U)
BRACKET(VF)
EYE PIECE ASSY
Fig. 3-3-1 Connection for Service support system (1)
3
.3 SETUP
1. Setup for electrical adjustment with personal computer