Thursday, October 08, 2015

HITACHI 32LD7800 - HOW TO ENTER SERVICE MODE - ADJUSTMENTS

Hitachi 32LD7800TA (PW2L) LCD display Adjustment mode - Memory Initialize operation - Disassembly
Large-screen, high-definition LCD display panel
The 32-inch LCD display panel, with a resolution of 1366 (H) x 768 (V) pixels, creates a high-definition, large screen (aspect ratio: 16:9) and low-profile flat display. Free from electromagnetic interferences from geomagnetic sources and ambient power lines, the panel produces high-quality display images free from color misconvergence and display distortion.
High Performance Digital Processor
A wide range of input signals can be handed, including composite, component, and HDMI.High Definition Digital Processor creates the fine-textured image with dynamic contrast. In addition, it corresponds to a broad array of personal computer signals, from 640 x 400 and 640 x 480 VGA to 1600 x 1200 UXGA.(Analog Input)
Easy-to-use remote control and on screen display system
The remote control included eases the work of setting display controls. Further, the on-screen display system,displays the status of signal reception and display control settings in an easy-to-view fashion.
Power saving system
The International ENERGY STAR power saver feature saves power consumption automatically when input signals are not available.  When connected to a VESA DPMS-compliant PC, the monitor cuts its power consumption while it is idle.
ADJUSTMENT MODE
> Using the center of the upper control buttons with the set turned off (standby) can activate it.
> Press the SUB-POWER button, INPUT SELECT button and button at the same time, and hold for more than 5 seconds.  The set turns on in adjustment mode with OSD.
Changing data and Selecting Adjustment code
> When the set is in adjustment mode, the cursor ◄► and OK buttons of the remote control or the control buttons may be used as the adjustment keys.
Buttons are used for selecting adjustment code.
▲▼ Buttons are used for changing data values.
> OK button is used for confirming the data.
> After finishing the necessary adjustment press MENU button. Adjustment mode is released and the set returns to normal condition.
Memory Initialize operation
NOTE: The execution of this function returns the adjustment codes to the preset values, therefore, adjustment data will be lost.
> Enter Adjustment Mode.
> Select MEMORY INIT adjustment code (No.658) and change the data value from 0 to 1.
> Activate MEMORY INIT by pressing OK button for more than 3 seconds.
> Select No.525 and change data value from 1 to 0.
Check that the receiving channel goes to P1. Unit is set to preset values.
How to get to Burn-in mode
This mode displays the test patterns of some single colour raster in turn. These signals are from built-in generator of LCD panel. So it can be presumed that maybe the panel has some trouble when the screen of Burn-in mode is abnormal.
> Using the centre of the upper control buttons with the set turned off (standby) can activate this mode.
> Press the SUB-POWER button, INPUT SELECT button and VOLUME DOWN button at the same time, and hold for more than 5 seconds.
> The set turns on with single colour raster and the OSD of [BURN IN: ON].
To escape from this mode, press the SUB-POWER button, INPUT SELECT button and button at the same time, and hold for more than 5 seconds. Burn-in mode will be released.
How to recover the remote and the centre of the upper key function
If remote and the centre of the upper key cannot operate after miss set special function by the center of the upper keys, these functions can recover by below method.
> Press the SUB-POWER button, INPUT SELECT button and button at the same time, and hold for more than 5 seconds.  The set turns on the service menu mode.
Select No.535 and data set from [0] to [1].
Or
Press the SUB-POWER button and button at the same time, and hold for more than 5 seconds.
How to check method of the use accumulation time for panel.
Select No.518 of Service Adjustment Menu.
Signal circuit self-diagnosis function
This function is for the failure of the signal circuit, for example the phenomenon as below
"Sometimes power turns off abnormally." "Sometimes picture disappears abnormally."
To enter to this Self-Diagnosis mode, follow the next steps
The Power Cord should be connected to AC line and the Main Power switch should be turned on.
Turn the power off by the SUB-POWER button of the monitor or the remote control.

> Press the SUB-POWER button and button on the centre of the upper of the monitor at the same time,
and keep it for more than 5 seconds after the power turned on.
> The monitor will be turned on, and it will display On-Screen Display of the Self-check result and the failure history as below.  Any operation would cancel the Self -Diagnosis mode.
The following table shows the OSD symbols and contents of failure PWB in which failure most probably would be allocated according to the number of blinks.
If you clear history of failure, make FACTORY RESET: Enter the factory setting mode; press the SUB-POWER button, INPUT SELECT button and button on the centre of the upper of the monitor at the same time. 
And keep it for more than 5 seconds after the power turned on.
Assembly - Disassembly
Be careful not to give stress on the power boards R141 and R133 by pushing the cables while dealing with the clamp of cables next to the power boards.
Detaching the cable from the clamp
> Detach the connector from the power board.
> Twist off the screws for the power board, and detach the power board.
> Then, detach the cable from the clamp.
Attaching the cable from the clamp
> Put the cables through the clamp.
> Fasten the power board with screws.
> Attach the connector to the connector base of its power board.
Make sure to set the guide posts of unit deep enough into the hole on the in display when inserting the video unit.
In case that it is stuck during the mounting, please readjust the position without pushing it by constraint.
PWB LAYOUT
How to clean the LCD screen panel of the monitor
Before cleaning the monitor, turn off the monitor and disconnect the power plug from the power outlet. To prevent scratching or damaging the LCD screen face, do not knock or rub the surface with sharp or hard objects. Clean the screen with a soft cloth moistened with warm water and dry with a soft cloth. If it is not enough, then use a cloth with mild detergent. Do not use harsh or abrasive cleaners.
How to clean the cabinet of the monitor
Use a soft cloth to clean the cabinet and control panel of the monitor. When excessively soiled dilute a neutral detergent in water, wet and wring out the soft cloth and afterwards wipe with a dry soft cloth.  Never use acid/alkaline detergent, alcoholic detergent, abrasive cleaner, powder soap, OA cleaner, car wax, 
glass cleaner, etc. especially because they would cause discolouration, scratches or cracks.