JVC GY-HM790U User Manual

SERVICE MANUAL
COPYRIGHT © 2010 Victor Company of Japan, Limited
No.HC034<Rev.001>
2010/11
HD MEMORY CARD CAMERA RECORDER
HC034<Rev.001>201011SERVICE MANUAL
GY-HM790U, GY-HM790CHU,
GY-HM790E, GY-HM790CHE
COPYRIGHT © 2010 Victor Company of Japan, Limited
Note :
Lead free solder used in the board (material : Sn, Ag, In, Bi, melting point : 227 Centigrade)
TABLE OF CONTENTS
1 PRECAUTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-3
1.1 SAFETY PRECAUTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-3
2 SPECIFIC SERVICE INSTRUCTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-5
3 DISASSEMBLY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-5
3.1 GENERAL DESCRIPTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-5
3.2 HOW TO REMOVE THE EXTERIOR PARTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-5
3.3 HOW TO REMOVE THE OPTICAL BLOCK ASSEMBLY. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-7
3.4 HOW TO REMOVE THE MAJOR BOARDS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-8
3.5 HOW TO REMOVE THE HANDLE ASSEMBLY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-11
3.6 HOW TO REMOVE THE VIEW FINDER ASSEMBLY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-12
4 ADJUSTMENT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-14
4.1 FUNCTIONS REQUIRED FOR ADJUSTMENTS, SETUP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-14
4.2 STANDARD SETUP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-14
4.3 ADJUSTMENT MENU . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-15
4.4 FLOWCHART OF ADJUSTMENTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-17
4.5 CAMERA ADJUSTMENTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-18
5 TROUBLE SHOOTING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-22
5.1 SERVICE MENUS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-22
5.2 EEP-ROM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-27
5.3 HOW TO UPDATE THE FIRMWARE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-28
5.4 PRECAUTIONS WHEN CHANGING BOARDS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-30
* The illustration shows the GY-HM790E with the supplied viewfinder, microphone and lens attached.
* GY-HM790CHU/GY-HM790CHE does not come with a lens.

JVC GY-HM790U Specifications

General

Sensor type	CCD
Total megapixels	- MP
Optical sensor size	1/3 \
Digital zoom	- x
Optical zoom	14 x
Image stabilizer	No
Focal length range	4.4 - 61.6 mm
Interchangeable lens	Yes
Focal length (35mm film equivalent)	32 - 448 mm
Camcorder media type	Memory card
Compatible memory cards	SDHC
Internal storage capacity	- GB
Built-in flash	-
Display diagonal	4.3 \
Display resolution	800 x 480 pixels
Display resolution (numeric)	410000 pixels
Viewfinder resolution	1226000 pixels
Viewfinder screen size	0.45 \
Camcorder type	Shoulder camcorder
Product color	Black
Video resolutions	1280 x 720, 1440 x 1080, 1920 x 1080 pixels
Supported video modes	1080i, 576i, 720p
Video formats supported	MPEG2
Maximum video resolution	1920 x 1080 pixels
Bitrate at maximum video resolution	35 Mbit/s
Maximum image resolution	- pixels
Headphone connectivity	3.5 mm
USB 2.0 ports quantity	USB 2.0 ports have a data transmission speed of 480 Mbps, and are backwards compatible with USB 1.1 ports. You can connect all kinds of peripheral devices to them.
Component video (YPbPr/YCbCr) out	1
USB 3.2 Gen 1 (3.1 Gen 1) Type-A ports quantity	0
Battery capacity	- mAh
Battery life (max)	- h
Storage temperature (T-T)	-20 - 60 °C
Operating temperature (T-T)	0 - 40 °C
Storage relative humidity (H-H)	0 - 85 %
Operating relative humidity (H-H)	30 - 80 %

Weight and Dimensions

Weight	3.7 g

Summary

Precautions and Safety

Safety Precautions

Essential safety measures to be followed during servicing to maintain product compliance and prevent hazards.

Precautions during Servicing

Specific cautions for handling parts, wiring, and components to ensure safety and proper repair.

Safety Check after Servicing

Post-service tests including insulation, dielectric strength, clearance, and leakage current checks.

Service Instructions and Disassembly

General Description

Overview of servicing procedures and general cautions before starting work.

How to Remove Exterior Parts

Step-by-step guide for removing outer covers and assemblies, including screw identification.

How to Remove Major Boards

Detailed instructions for removing main circuit boards like AUDIO, CAM, SDI, and CODEC boards.

How to Remove the Handle Assembly

Procedure for disassembling and removing the camera's handle component.

How to Remove the View Finder Assembly

Steps for disassembling and removing the viewfinder unit, including lens and VF boards.

Adjustment Procedures

Functions Required for Adjustments

Lists necessary instruments, special implements, and setup for performing adjustments.

Standard Setup

Diagram illustrating the standard equipment setup for calibration and adjustment.

Adjustment Menu

Comprehensive list of adjustable parameters with their modes, ranges, and display order.

Camera Adjustments

Specific adjustment procedures for encoder, cam, flare, and black levels.

HOB/VT White blemish adjustment

Procedure to correct horizontal and vertical white blemish issues using specific adjustment menus.

Troubleshooting and System Menus

Service Menus

Explanation of service menu hierarchy and operation for firmware, version check, and advanced functions.

EEP-ROM

Details EEP-ROM contents, purpose, and data reset behavior upon board replacement.

How to Update the Firmware

Step-by-step guide for updating the camera's firmware using an SD memory card.

Precautions When Changing Boards

Guidelines for firmware version updates and adjustments required after replacing boards.