XOCECO PS42K8 User manual

COLOR TELEVISION
PS42K8

1
Note: This maintenance manual is intended only for the reference of the maintenance people.
Please pay attention to the following points before carrying out the maintenance work.
1.Safety Instructions
Please read the “Points for attention for the Maintenance & Repair of PDP”and “Criterion
for Identifying the Defects on Screen” as below, before inspecting and adjusting the TV set.
<1>. “Points for attention for the Maintenance & Repairof PDP”
To avoid possible danger, damage or jeopardy to health and to prevent PDP screen
from new damage, the maintenance people must read the following carefully. If they ignore
the following warnings, there will be deathful risks:
1). Screens vary from one model to another and therefore not interchangeable. Be sure to
use the same type of screen in the replacement.
2). The operation voltage is approximately 350v for PDP module (including screen, driving
circuit, logic circuit and power module). If you want to conduct maintenance work on PDP
module when the set is in normal operation or just after the power is off, you must take
proper measures to avoid electric shock and never have direct contact or touch with the
circuitry of the working module or metal parts. That’s because within a short time relatively
high voltage still remains on the capacitor of the driving part even after the power is off.
Make sure to begin relevant maintenance operation at least one minute after the power is
off.
3). Don’t apply on the module any power supply that is higher than the specification.If the
power supply used deviates from the value given in the specification, there might be a
possibility of leading to fire or damage to the module.
4). Never have operation or mounting work under unsuitable environment such as areas in
the vicinity of water – bath room, laundry, water chute of kitchen – sources of
fire,heat-radiation parts or direct exposure to sunlight. Otherwise there will be kickbacks.
5). In case foreign substances such as water, liquid, metal slices or others fall into the
module carelessly power must be cut off immediately. Keep the module as it is and do not
move anything on the module. Otherwise it might be possible to contact the high voltage or
cause shock short circuit so that it may lead to fire or electric shock.If there is smoke,
abnormal smell or sound from the module, please cut the power off immediately. Likewise
in case the screen doesn’t work when the power is on or during the operation, please also
cut off the power at once. No more operation in this case. Do not remove or plug its
connection wire when the module is in operation or right.after the power is off. That’s
because there remains a relatively high voltage on the capacitor of the driving circuit. If
there is a need to remove or plug in the connection wire, please wait at least one minute
after the power is off.
8). Considering the module has a glass faceplate, please avoid extrusion by external force
lest it should cause glass breakage that may get people injured. Two people are needed in
cooperation to move this module lest contingency takes place.
9).The complete TV set is designed on the basis of full consideration of thermal dissipation

2
by convection, with the round hole on the top for heat emission. To avoid overheat, please
do not have any covering on the hole during normal operation and never put it in the place
where the space is narrow and in bad ventilation.
10).There are quite a number of circuits in PDP that are integrated ones. Please be on
guard against static electricity. During maintenance operation be sure to cover yourself with
anti-static bag and before operation make sure to have it sufficiently grounded.
11).There are a big number of connection wires distributed around the screen. Please take
care not to touch or scuff them during maintenance or removing the screen, because once
they are damaged the screen will fail to work and it’s not possible to repair it.
12). Connector for the circuit board of the screen part is relatively fine and delicate. Please
take care in the replacement operation lest it should get damaged.
13).Special care must be taken during transportation and handling because strenuous
vibration could lead to screen glass breakage or damage on the driving circuitry. Be sure to
use a strong outer case to pack it up before transportation or handling.
14).Please put it for storage in an environment in which the conditions are under control so
as to prevent the temperature and humidity from exceeding the scope stipulated in the
specification. For prolonged storage please cover it with anti-moisture bag and have them
piled and stored in one place. The environmental conditions are tabulated as below:
Temperature Scope for operation 0～50centigrade
Scope for storage -15～60centigrade
Humidity Scope for operation 20%～80%
Scope for storage 20%～80%
15). If a fixed picture is displayed for a long time, difference in its brightness and color may
occur compared with movable pictures. But it doesn’t show any problem and the reason is
that there is reduced density of fluorescent powder in the former. On the other hand, even if
changes take place in the picture, it can keep its brightness for a period of time (several
minutes). It’s a feature inherent with plasma and it’s not abnormal. However please try as
much as possible to avoid showing a still picture of high brightness for a long time during
operation.
16). As a digitalized display devise, this module is provided with error diffusion technology
and the gray scale and false enhancement of contour can be displayed by reusing of
sub-field. As compared with cathode ray tube, it can be found in the moving picture that at
the brim of the face of a person there are some wrong colors.
17). During the display of graph (indicating the gradual change in brightness horizontally or
vertically) resulting from gray scale test it can be found that the brightness for the two
adjacent levels is uneven. This is caused by the reuse of sub-field, the display of load
rectification and the eletrolyzation.
18).The screen front plate is of glass. Please make sure that the screen has been put in
place during erection. If it is not in place before the erection begins it may lead to screen
crack or breakage.
19).Make sure the screw used in the mounting of the screen is of the original specs lest it
should cause damage to the screen due to mismatch. Special care should be taken not to
use too long or too big screw.

3
H
W/4 W/2 W/4
H/4
H/2
H/4
20). Care must be taken to guard against dust during assembling or dismantling, especially
to avoid dirt from falling in between the screen and the glass lest it should harm the
receiving and viewing effect.
21). There is piece of insulator stuck on the rear chassis corresponding to the power supply
board. It is used to isolate the cool part from the hot part. Please take care to keep it intact
lest it should become a potential safety trouble.
22). In addition to plasma screen, the glass is a part of high value. It has such functions as
anti-radiation, adjustment of color temperature etc. Please handle it carefully.
<2>.“Criterion for Identifying the Defects on Screen”
The PDP produced by our Company at present uses the following criterion for
identifying the defective points:
2.1,Model PS－42D8:
There may appear three kinds of defective points for this model as shown in Fig.1, i.e.,
bright spot (remain bright); dark spot (non-illuminating); flickering spot (continuously
flickering). However they should not exceed the specification as in table 1. Otherwise the
product shall be deemed as sub-standard.
Figure 1 Defective Points
Table 1 Criterion for Three Kinds of Defective Points
Kind Area A Area B Remark
Dark spots No more than 2 No more than 8
Bright spot No more than 1 No more than 2
Flickering spot No more than 1 No more than 2
Total number of
defective points in A
and B shall not
exceed 8. The
distance between
two defective points
shall not be shorter
than 15mm.
Zone B
Zone A

4
2.Method of Debugging
1. Adjustment for MS42K8 excludes 3.1and 3.2
2.Adjustment and calibration Equipment
PM5518(Video signal generator), K-7253(VGA signal generator),CA100 (White
Balancer)
3.Flow process of Adjustment and calibration
For flow process of Adjustment and calibration, see Figure 1
Check if DDC has been FLASH written.
Production of CPU board and AV or TV board on the
line.
Check CPU board
CheckAV or TV board
Combined test for general assembly
Connect to central signal source, check if various T
V
functions (station skipping, analog control etc), check i
f
the output of earphone and speaker is normal
Input AV/S, HDTV signal and check various
functions under terminals
Input VGA signal (one format) and check if display is
normal in the state of PC and various functions
(analog control, line/field center etc.)
Check accessories and then packing
Figure 1 Flow process
of Adjustment and
calibration

5
4.AV/TV Board adjustment
Adjust the potential meter VR12 on the power supply board, measure the test point
TP1(12VAMP) on the AV/TV board and set the reading at 15±0.05 V.
5. CPU board adjustment
Connect CPU board, push button board and AV or TV board, put power on, and
observe if the display is normal.
Method to enter the factory menu: Continuously push “ VOL+”“Mute” “ Video” keys
to enter the factory menu. Push the “ENTER” key to select different adjustment item when
the first line of each adjustment item is in high brightness. Push “ENTER” key after the
mode is selected with VGA and DV1 input and select three color temperatures
6500K,9300K,and 12000K. Push “MENU” to quit the factory menu.
5.1 EPROM initialization
Enter the first page of factory menu, push “ENTER” key after the selection of Clear
EEPROM, and shut off the power supply after the appearance of “OK”.
5.2 VGA channel adjustment
5.2.1 VGA channel mode preset
Input VGA signal of K-7253(PATTERN 5:Final Test),select TIME301(640*350/70Hz),
push”AUTO”key to automatically set the picture full screen. Likewise, automatically
adjustTIME302(720*400/70Hz), TIME303(640*480/60Hz), TIME311(800*600/60Hz),
TIME313(1024*768/60Hz),TIME315(640*480/75Hz),TIME316(800*600/75Hz),TIME317(10
24*768/75Hz),TIME319(1280*1024/75Hz),and TIME339(1280*1024/60Hz) respectively.
5.2.2 AGC adjustment of VGA channel
Adjust ADC-gain to 15
5.2.3 White balance adjustment of VGA channel
Input K-7253 TIME303(640*480/60Hz),PATTERN471,and the signal of 8 grades of
grey density. Enter the adjustment menu of white balance. Use the white balancer to adjust
second and seventh grades.
Select mode to be 6500K,adjust offset_R, offset_G, offset_B, so that the second grade
color coordinates are 313,329 and the brightness about 2 nit. Adjust gain_R, gain_G,
gain_B so that seventh grade color coordinates are 313,329. Adjust offset_R, offset_G,
offset_B and gain_R, gain_G, gain_B,again and again until two grads of grey density are all
set to 313,329.
Select mode to be 9300K,adjust offset_R, offset_G, offset_B,so that the second grade
color coordinates are 285,290 and the brightness about 2 nit. Adjust gain_R, gain_G,
gain_B so that seventh grade color coordinates are 285, 290. Adjust offset_R, offset_G,
offset_B and gain_R, gain_G, gain_B, again and again until two grads grey density are all
set to 285,290.
Select mode to be 12000K.Adjust offset_R, offset_G, offset_B,so that the second grade
color coordinates are 270,283 and the brightness to be about 2 nit. Adjust gain_R, gain_G,
gain_B, so that the seventh grade color coordinates are 270, 283.Adjust offset_R, offset_G,
offset_B and gain_R, gain_G, gain_B, again and again until two grads grey density are all
set to 270,283.
Note: The value of gain_R, gain_G, gain_B should not exceed 128, and at least one
of them must be guaranteed to be 128.
5.3 AV/TV channel adjustment

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5.3.1 VCO, OPTION, sub-brightness, and sub-contrast adjustment
Input the AV color bar signal (PM5518 COLOUR BAR 100%)to VIDEO terminal, enter
the first page of factory page, select auto color, push “ENTER” key. Two seconds later, OK
appears and shows the VCD adjustment is over. Set the value of option to 9, s-bright to 150,
s-contrast to 130,max-volume :PS42K8 and 14/MS42K8 to 66.
Enter the adjustment page of VPC3230, adjust the data of the page to be 0,1,3,3,0,1,9
from top to bottom.
5.3.2 White balance adjustment of AVTV channel
Input AV signal (PM 5518, 8 grades of grey density), enter the adjustment menu of
white balance. Use the white balancer to adjust second and seventh grades.
Adjust offset_R, offset_G, offset_B, so that the second grade color coordinates are 255,
245, and the brightness to be 2.5 nit. Fix gain_B to 128,adjust gain_R,gain_G,,so that the
seventh grade color coordinates are 288, 285, Adjust offset_R, offset_G, offset_B and
gain_R, gain_G, again and again until two grads grey density are all set to the specified
value.
5.4 White balance adjustment of D4 channel
Input YPbPr signal of K-7253 to D4-terminal,input eight grades of grey density signal of
TIME380(480i)PATTERN471, adjust s-bright to 120,S-contrast to 130. Enter the
adjustment menu of white balance,adjust second grade with balancer. Adjust offset_R,
offset_G, offset_B so that the second grade color coordinates are 255,245 and the
brightness about 2.5 nit.
Input eight grades of grey density signal of mode TIME392(480p),TIME394(720p)and
TIME396(1080i)separately. Repeat above operation, so that the second grade color
coordinates are 255,245 and the brightness about 2.5 nit.
6. Functional inspection
6.1 TV function
Enter the search menu auto search, connect the central signal source to RF-TV
terminal, check if there is station skipping.
6.2 BS connector
Input BS satellite signal to RF-BS terminal,check BS-5,BS-7,BS-11,if the picture and
sound of three channels are normal. Use oscillograph to check if the terminal output is
normal (Bit Stream is 1 Vpp data flow; Detection Out is 1.34 Vpp detective wave signal).
6.3 AV/S,D4 terminal
Input AV/S, HDTV signal, check if they are normal.
6.4 VGA connector
Insert VGA signal connector, input signal with format 640x480@60 Hz VGA, check if
the display is normal. If there is interfere in picture, push the adjustment key on the remote
control one more time and check if the display is normal.
6.5 Sound channel inspection
Check if the speaker output of each channel is normal.
6.6 For factory preset, see table. 1

7
Table 1. For factory preset
3.Introduction of working principle of Plasma TV PS-42K8
The plane screen technology of Plasma is the latest state of art, and it is the best
selection of high quality picture and big pure flat screen. The plasma display PDP is a kind
of display device by means of gas discharging. This kind of screen adopts plasma tube as
light emitting unit. PDP panel consists of many pixel units (plasma tube), such as the
screen of the 42” PDP sold currently, which consists of 852*480 pixel units. Each pixel unit
includes three sub-pixel units. Each pixel unit is a plasma tube, which displays red, green
and blue separately. Each chamber to which each plasma tube corresponds is filled with
neon or xenon gas. When high voltage is applied between the poles of plasma tubes, the
gas sealed in the chamber of plasma tube between two layers of glass of radiates
ultraviolet light, which in turn excites the fluorescence powder of three base color - red,
green and blue - on the plane screen radiates visible light. Each plasma tube, as a pixel unit,
produces different pictures with different color and grey density through various
combinations of its changes in brightness and color, which is similar to the light emission of
CRT. Compared with other displays, the plasma technology has apparent differences. Its
construction and composition is ahead of other technologies. The working principal is
similar to normal fluorescent lamp. The color picture of the TV is formed of the light
emissions by each pixel unit of fluorescent powder. Thus, the picture looks bright, fresh,
clean and well focused. Besides, The most outstanding characteristic of plasma TV is that it
can be made super thin, and it’s very easy to make the screen as large as over 40 inches
while the thickness is less than 100 mm. (The thickness of our PS-42K8 is 79mm only,
which is the thinnest in the market)
1. For the working principle and process flow of PS42K8, see block diagram
of complete TV set. The signal flow process is described briefly as follows:
By way of TUNA01, the RF signal of satellite TV, BS-RF produces color full TV signal
TV-BS and audio frequency signal BS-R/L. By way of TUNA02, the RF signal of broadcast
TV produces full color TV signal TV-IN2 and second IF sound signal SIF. The VIDEO signal
selected by PI50V330(NA07)through TV-BS and TV-IN2 is sent to video decoder
VPC3230(U29). Video signals AV,SVHS and YcbCr are sent to U29 respectively. After the
selection of above four video signals, one route is as AV OUT, another route is for color
decode. Then the signal in the format of ITU-R656 of 8 bits is sent to FLI2310(U13)for
progressive processing.
D4 is sent to MST9883(U30), where the signal undergoes digit to analog conversion
Item Factory
Preset Item Factory Preset Item Factory Preset
Picture
mode NATURE OSD language Japanese BS POWER ASSOCIATE
Sound
mode NEWS VGA color temperature 9300 AV1/DECODER AV
N/R WEAK SRS ON
SCREEN 16:9 BALANCE ON

8
and then it is also sent to U13 in YUV format of 24bit.
24bit RGB signal is output and sent to main processing IC JAG-ASM(U12) after the
above two routes of signal are processed in matrix , color density, and tint in U13.. Another
route of RGB signal of computer VGA is also sent to U12, where two routes of signal are
subject to selection and processing for picture format. One route RGB signal of VGA
undergoes A/D conversion before being subject to selection and digit display processing
together with another route of signal, including OSD, GAMMA calibration, brightness and
contrast processing. These signals are changed into the format of 1024*768. The above
RGB signal of 24 bit is output to LVDS converter DS90C385(U31)of; where it is converted
into four pairs of low voltage differential signal acceptable for PDP screen. Then, the signal
is sent to PDP screen for picture display.
The audio R/L of left and right sound channels D4,YCbCr and BS undergoes selection
and is then sent to MSP3420(NA04).AV,SVHS and R/L of VGAare sent to NAQ04.In NA04,
the second sound IF( SIF) is demodulated into audio signal together with other four routes
of sound signal being switched for selection. The selected R/L after the processing in
volume and sound effect is then output. One route MONO sound is for AV OUT, the other
route is sent to M62494(NA08)of SRS sound field processor for SRS processing. The
signal, after sound power amplification by TPA3001(NA10,NA11), is for driving the speaker.
BS tuner outputs other route BIT/DET. The power is supplied by power supply board on
PDP screen and then transformed into different required power supplies.

U12
SCALER
JAG-ASM
U13
DEINTER
LACER
FLI2310
RGB
24bit
RGB
VGA
PANEL
RGB
24bit
U19
SDRAM
U20
SDRAM
U14
SDRAM
YCbCr
AV
C
Y
RF
ITU-R656
TUNA01
TV
SIF
8bit
U29
VIDEO DECODER
VPC3230
AV-V OUT
U30
ADC
MST9883
U3
EEPROM
U2
MICRO-CONTRLER
TSC80251G2D
U4
FLASHMEMORY
IR
SIF
S
VGA
AV-MONO OUT
NA04
AUDIO
PROCESSOR
MSP3420
NA08
SRS 3D STEREO
CONTROLLER
M62494
2.BLOCK DIAGRAM
I C BUS
2
24bit
YUV
KEY BOARD
R/L
TUNA02
BIT/DET
BS-RF
NA07
TV-BS
TV-IN2
PI5V330
AV
NA03
HEF4052
D4
YCbCr
9
V
MONO
U31
LVDS
DRIVER
DS90C385MTD
SPEAKER
R/L
NA10
NA11
AUDIO
AMPLIFIER
TAP3001
R/L
BS
D4

10
4.IC BLOCK
1．MSP3420

11
2．VPC3230

12
3．JAG-ASM

PS42K8 WIRING DIAGRAM
335-42001-00
PANEL
LOGIC CIRCUIT
BOARD POWER BOARD SOUND BOX PART
POWER FILTER
BOARD
667-PS42K8-40
ADUIO-VIDEO PROCESSOR BOARD
667-MS42K8-56
CPU BOARD
667-PS42K8-05
KEYSETS

14
5.Distribution of the Circuit Board of Different Screens and their
Functions
42SD(Type:S42 SD-YD04,Code No:335-42001-00)
Parts
designation Function
Power supply
board Provide power for the operation of complete TV set
Logic board Convert the LVDS signal from the processing board into the one displayable by
screen
Addressing circuit Addressing circuit for screen display, directly driving the address electrode on
the screen (Vertical electrode, totally 852X3electrode)
X driving X electrode（horizontal common holding electrode）driving circuit
YX driving Yelectrode（horizontalscanning, holding electrodes,total 480 electrode）driving
circuit
X driving
Power supply board
Y driving
Logic board
Addressing circuit

15
8.PCB partsand number
Parts name Parts number Main parts and number
CPU board 667-MS42K8-56
U12 JAG-ASM (353-0JAG0-00)
U13 FLI2310 (353-23100-00)
U29 VPC3230D (353-32300-80)
U30 MST9883B (353-98830-10)
U31 DS90C385MTD (353-03850-20)
U2 TSC80251G2D (353-80251-10)U4
AT49F002NT (352-49002-70)
video frequency
processor boards 667-PS42K8-40
NA04 MSP3420G-Q (353-34200-10)
NA08 M62494FP (353-62494-20)
NA10 NA11 TPA3001 (353-30010-10)
Remote parts 301-UPS42D8-09
key-press board
parts 667-PS42K8-05
Power filter board 667-PS42D8-51

16
Short circuit the pin 8 (PS-ON)
of X709 to the ground, the
n
check power
.
9.Diagram of Normal Trouble Shooting
1．“Three no”, i.e., no raster, no picture and not sound:
Ifpowerindicationlampislit
yes no
normal
normal abnormal normal abnormal
JI
Normal abnormal
normal
Note:Power supply for PDP is provided with over current and over voltage protection functions.
If there is over current or over voltage, this protection will function and no output.
Three no
check5V-STBY
Cutoff the connection
b
etween power board
and signal process,
check5V-STB
Cutoff the connectio
n
x2 between main boar
d
and video process.
Board,then determine
which board is
abnormal
Power boar
d
problem
Check powe
r
es
p
. D3.3V
N
501abno
rmal
Check supply,
crystal oscillation
for N501andN601
Pull ou
t
X709 chec
k
Check N501an
d
N
601
Check supply fo
r
N
102,N204,N302,
N
403,crystal
oscillation and bus line
Short
circuit in
Power boar
d

17
2．There is sound but no picture:
yes no
no yes
normal
Normal abnormal
abnormal
Normal abnormal
NOTE:
 Setting up for the self check of the screen:
 For 42”SD screen (S42SD-YD04):Push down 2 and 4 and push up 3 of
SW2001on the logic board;
 For 50”HD screen (S50HW-XD02):Push down 1 and 4 and push up 2, 3, 5, 6 of
SW2001on the logic board;
Please make sure resume it to the original status when the check is over.
With sound but no picture
If there is interface for switch on
Check if no image for all other
channels
N
501 an
d
peripheral Change into 4
check
program
If oscilloscope is
ready，first measure
the wave form o
f
signal X60
Pull X604,X709,short circuit pin 8 o
f
X709 to the ground,set logic boar
d
switch to self check signal,see if the
screen appears white when switched on
Check input signal of N601an
d
power supply Screen damage
d
N
601damage
d
Check N501and the circuit
of output part

18
3．There is picture but not sound.
If there is output from XA04of sound power amplification board
No
Yes
yes no
yes no
4．A certain channel is abnormal
1) AV/YCRCB no picture
yes no
no yes
no yes
There is picture but no sound
Sound box damage
d
Sound power ampl. or other peripheral circuit have problem. Check
power supply,if SHUTDOWN pin control is normal and if output
short circuited or other problems that cause protection to work.
Measure if there is signal in pin 2
of sound
p
ower am
p
lf.2
Measure if the sound input of the
present channel corresponding to
NM2 is normal
MSP3440 or other peripheral
circuit have
p
roblen
m
Check different levels of
circuit following input audio
signal channel
If Check U29 pin72
(S-VIDEO),pin73(VIDEO) and
pin5,75 (YCRCB)signal input
Check U29
pin27,31~34,37~40
output and ITU-R 656
Check U29
Check RP3~RP9 and U13
FLI2310 out
p
u
t
Check U29
Check U13 FLI2310 Check U12

19
2) D4 no picture
yes no
yes no
否yes
Check U30 pin48(Y) and pin49 (SOG)
Check D4 to U30
Check RP36~RP41,RP141
and U30
Check RP3~RP9 and U13
FLI2310
Check U30
Check U13 FLI2310 Check U12