Daewoo DPP-42A1LASB Service Manual page 75

1. Application Object
This standard is applied to the PDP42V7#### PDP Module
which is manufactured by the manufacturing team of PDP
promotion department or elsewhere.
2. Notes
(1) Without any special specification, the Module should be at
the condition of preliminaries more than 10minutes before
adjusting.
- Service signal : 100% Full White signal
- Service DC voltage : Vcc: 5V, Va: 65V, Vs: 187V
- DC/DC Pack voltage : Vsc=115V
-Vy: -85V
- Preliminaries environment : Temp
humidity (65!10%)
(2) Module should get the Aging for the equilibrium after finish
the assembling. Aging condition is shown below.
- Service signal: 100% Full White, Red, Green, Blue pattern
signal(Service time of each pattern : within 5minutes/cycle)
- Service DC voltage : Match the voltage with the set up
voltage in the first adjustment.
- Aging time : More than 30 minutes
- Aging environment : Temp (25!2°C), Relative humidity-
Less than 65%
(3) Module adjustment should be followed by below sequence.
- Setting up the Vsc/-Vy voltage(Vsc=115V, -Vy=-85V)
- Adjusting the voltage wave form(Refer to adjustment)
- 25!5°C, 65!10%
(4) Without any special specification, you should adjust the
Module in the environment of Temp (25!5°C) and Relative
humidity (65!10%)
Caution) If you let the still image more than 10 minutes(especially
The Digital pattern or Cross Hatch Pattern which has
clear gradation), after image can be presented in the
black level part of screen.
3. Adjustment after Assembling
3-1. Using Tools
(1) Digital oscilloscope : More than 200MHz
(2) DVM(Digital Multimeter) : Fluke 87 or similar one
(3) Signal generator : VG-825 or similar one
(4) DC power supply or PSU
- DC power supply for Vs (1) : Should be changeable
between 0V to 200V/ more than 10A
- DC power supply for Va (1) : Should be changeable
between 0V to 100V/ more than 5A
- DC power supply for 5V (1) :Should be changeable
between 0V to 10V/ more than 10A
- DC-DC Converter Jig (1) : The Jig which has equivalent
voltage output of PDP42V7#### Module after taking the
Vs, Va, 5V voltage
- Voltage stability of power supply : Within !1% for Vs/Va,
within !3% for 5V
Ⅲ. Adjustment
3-2. Connection diagram of measuring
instrument and setting up the initial
voltage
(1) For connection diagram of measuring instrument,
refer to Fig. 1.(Connection diagram of measuring
instrument that adjusting the voltage wave form)
(2) Setting up the initial voltage(Voltage Label)
Vcc: 5V, Va: 65V, Vs: 187V
But, Initially setting up voltage can be changed by the set
up range according to the Module's characteristic.
3-3. How to Adjust
(25!5°C), Relative
(1) Adjusting Vset-up Voltage Wave form
① Connect the measuring instrument to be (Fig. 1).
② Turn on the measuring instrument with Caution of (Fig. 1).
③ Connect the oscilloscope probe to B39(Bead) of Y B/D
④ Turn the VR1 of Y B/D and make the "A" waveform Fig.
(2) Adjusting Vset-down Voltage Wave form
① Turn the VR2 of YSUS B/D and make the "B" waveform
(3) Checking the DC/DC pack voltage
① Convert the signal of signal generator to the 100% Full
② Connect the GND terminal of DVM to the right leg of R53
③ Connect the GND terminal of DVM to the right leg of
- 7 -
bottom and GND.
2 to be 10!2µs.
Fig. 2 to be 100!2µs.
(Fig. 2) Y, Z set-up Waveform
White signal.
on the Y B/D and set the Plus terminal to the left leg of
R53 to check the Vsc voltage(115!1V) and when there is
abnormality in voltage turn the variable resistor(VR3) of
DC/DC Pack(Vsc) PS1 on Y B/D to adjust.
R78 on the Y B/D and set the Plus terminal to the left
leg of R78 to check the -Vy voltage(-85!1V) and when
there is abnormality in voltage turn the variable
resistor(VR4) of DC/DC Pack(-Vy) PS1 on Y B/D to
adjust.