HITACHI 42PD8500TA - Plasma TV– How to enter to Service mode – Service mode adjustments – factory reset – LED Blinking code – Self diagnostics function - Plasma television repair and service

Category: Plasma Television Repair and service 

Contents  of this article 

• How to access service mode 
• LED Blinking and causes 
• Factory Reset Procedure 

HITACHI 42PD8500TA

Adjustment
How to get to Adjustment mode
Using the front control buttons with the set turned off (standby) can activate it.
Press the SUB-POWER button, INPUT SELECT button and DOWN 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 UP,DOWN ,LEFT ,RIGHT  and OK buttons of the remote control or front panel may be used as the adjustment keys.
UP, DOWN buttons are used for selecting adjustment code.
LEFT,RIGHT 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.
Procedure
(1) Enter Adjustment Mode.
(2) Select MEMORY INIT adjustment code (No.658) and change the data value from 0 to 1.
(3) Activate MEMORY INIT by pressing OK button for more than 3 seconds.
(4) Select No.525 and change data value from 1 to 0.
(5) Check that the receiving channel goes to P1. Unit is set to preset values.

Factory Reset
After all of the adjustments of main chassis are finished, perform FACTORY RESET.
Press the SUB-POWER button, INPUT SELECT button and button at the same time, and hold for more than 5 seconds.
The unit is set to factory settings.

Power Unit Vs, Va Adjustment

Turn on the set and perform pre-heat run more than 1 min on burn-in screen.
(1) Turn Vs ADJ to adjust Vs voltage to be within ±0.1V of the value specified in the label on the panel.
Adjust within ± 1V at Vs1
Adjust within ± 0.1V at Vs2

Receive full back pattern signal (or Video silence signal; but it will be automatically turned off after a few seconds by power save function.)

(2)Turn Va ADJ to adjust Va voltage to be within ±0.2V of the value specified in the label on the panel.
Adjust within ± 1V at Va1
Adjust within ± 0.2V at Va2

Connect voltmeter leads to Vs (or Va) and GND test points of the power unit.

(3) Reconfirm that Vs voltage remains within ±0.1V of the specified value. Readjust if it’s outside of the margin.

AGC Adjustment (Main)

(1) Turn on the set and perform pre-heat run more than 20 min.
(2) Receive AGC adjustment signal. CCIR ch-5: (175.25MHz) PAL B/G PHILIPS Field : -50dBm

Procedure
Receive AGC adjustment signal. Indicate Service Adjustment menu (Main).
Display the following signals at the same time. Service Adjustment No.13 (AGC Adjustment) No.15 (AGC Input)
Raise No.13 data value until No.15 data is saturated(This point: AGC-MAX)

With monitoring No.15 reduce No.13 data value and press [OK] key at the point when No.15 data comes down.

Video Color Temperature Adjustment (Cool)
Set the signal generator output as All White.
Component signal (480i)
Video level : 0.700Vp-p
Sync level : 0.300Vp-p
Setup level : 0V

Picture Menu is set as [RESET].
Confirm that the mode is set as Factory Adjustment mode.

Adjustment Procedures

After receiving the video signal, step down the two (or one) among adjustment No. 0, 1, 2 and adjust the values as shown below.
Note)
At least one of the data shoud be 255. Ensure that the service adjustment menu (sub menu) No. 0, 1, 2, are all set as 255.
Perform the following adjustment with the remote control
Set the CRT color analyzer (CA100) at the center of the panel.

Troubleshooting
How to get to Burn-in mode
This mode displays the test patterns of some single color raster in turn. These signals are from built-in generator of PDP panel. So it can be presumed that maybe the panel has some trouble when the screen of Burn-in mode is abnormal.
Using the front 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 color raster and the OSD of [BURN IN: ON].
To escape from this mode, press the SUB-POWER button, INPUT SELECT button and UP button at the same time, and hold for more than 5 seconds. Burn-in mode will be released.
How to recover the remote and front key function
If remote and front key cannot operate after miss set special function by front keys, these functions can recover by below method.
Press the SUB-POWER button, INPUT SELECT button and DOWN 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.
Self-Diagnosis Function
This chassis has 2 modes of self-diagnosis function.
(1) PDP panel check mode: It indicates the one latest record of the PDP panel failure with blinking of the power indication light (LED).
(2) Signal circuit check mode: It indicates the check result on some points of the signal circuit and the history of them with On-Screen Display (OSD).
PDP panel self-diagnosis function
This function is for a PDP panel failure with no picture.
To enter to this Self-Diagnosis mode, follow the next steps:
Preparation:
1) The Power Cord should be connected to AC line and the Main Power switch should be turned on.
2) Turn the power off by the SUB-POWER button of the monitor or the remote control.
Procedure:
1) Press the SUB-POWER button and DOWN button on the bottom of the monitor at the same time, and keep it for more than 5 seconds after the power turned on.
2) It generates red blinking series of the power indicator light.
3) Any operation would cancel the Self -Diagnosis mode.
4) The next table shows the PDP PWB in which failure most probably would be allocated according to the number of blinks.

LED BLINKING AND CAUSES 

Number of red blinks of power indication light	Presumed failing PWB of PDP panel
1	Logic
2	X-SUS
3	Y-SUS, SDM
4	X-SUS, Y-SUS, SDM, PSU
5	ABUS, ADM, PSU
6	ADM temperature
7	ADM temperature
8	All of above-mentioned PWB’s

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:
Preparation:
1) The Power Cord should be connected to AC line and the Main Power switch should be turned on.
2) Turn the power off by the SUB-POWER  button of the monitor or the remote control.
Procedure:
1) Press the SUB-POWER  button and UP button on the bottom of the monitor at the same time, and keep it for more than 5 seconds after the power turned on.
2) The monitor will be turned on, and it will display On-Screen Display of the Self-check result and the failure history as below.
3) Any operation would cancel the Self -Diagnosis mode

If you clear history of failure, make FACTORY RESET: enter the factory setting mode; press the SUB-POWER button, INPUT SELECT button and UP button on the bottom of the monitor at the same time. And keep it for more than 5 seconds after the power turned on.