Friday, October 02, 2020

JVC LT 30E45SU How to enter the service mode, circuit diagram, service adjustments and more

 LCD PANEL

This unit uses the flat type panel LCD (Liquid Crystal Display) panel that occupies as little space as possible, instead of the conventional CRT (Cathode Ray Tube), as a display unit.

Since the unit has the two polarizing filter that are at right angles to each other, the unit adopts "normally black" mode, where light does not pass through the polarizing filter and the screen is black when no voltage is applied to the liquid crystals.

PIXEL FAULT

There are three pixel faults - bright fault , dark fault and flicker fault - that are respectively defined as follows.

BRIGHT FAULT

In this pixel fault, a cell that should not light originally is lighting on and off.

For checking this pixel fault, input ALL BLACK SCREEN and find out the cell that is lighting on and off.

DARK FAULT

In this pixel fault, a cell that should light originally is not lighting or lighting with the brightness twice as brighter as originally lighting.

For checking this pixel fault, input 100% of each R/G/B colour and find out the cell that is not lighting.

FLICKER FAULT

In the pixel fault, a cell that should light originally or not light originally is flashing on and off.

For checking this pixel fault, input ALL BLACK SCREEN signal or 100% of each RGB colour and find out the cell that is flashing on and off.

HOW TO ENTER THE SERVICE MODE

(1) Press [MENU] key on the remote control unit simultaneously to display the MENU SCREEN.

(2) In the MENU SCREEN, press the [4] ,[7] ,[2] and [5] key.

(3) The following menu appears on the screen.

HOW TO EXIT THE SERVICE MODE

Press the [MENU] key to exit the Service mode.

 CHANGE AND MEMORY OF SETTING VALUE

 SELECTION OF SETTING MENU & ITEM

• FUNCTION  UP/DN  key: Select the SETTING MENU & ITEM

• [OK] key: Decision the SETTING MENU & ITEM

CHANGE OF SETTING VALUE (DATA)

• FUNCTION  Right/Left  key.

 MEMORY OF SETTING VALUE (DATA)

The setting value will be stored automatically when release the REMOTE CONTROL UNIT keys.

SERVICE MODE SETTING ITEMS

MEMORY IC REPLACEMENT

• This model uses the memory IC.

• This memory IC stores data for proper operation of the video and drive circuits.

• When replacing, be sure to use an IC containing this (initial value) data.


Block diagram


Circuit diagram - JVC LT 30E45SU, LT 30E45SJ, LT 30E45SU/Z, LT 30E45SU/N








Amplifier

Regulator circuit diagram



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