Saturday, December 19, 2015

ERAE EPT4200AP – MITSAI EPT4200AP – 42 inch Plasma TV - How to Troubleshoot - Service Mode

Almost all Plasma TVs (Displays), will display similar kind of fault symptoms; irrespective of its brand and screen size. The troubleshooting procedure and other details too is similar to them
Mitsai EPT4200 - ERAE EPT4200 - 42 Inch Plasma TV - Service Mode (Factory Mode)
How to enter Factory mode to adjust white balance
> PDP TV Power “On” =  Input select key on Remote control;  choose composite first and then PDP TV Power “Off”.
> PDP TV Power “Off” and INFO on the R/C = ERASE = ENTER Key
To exit the Factory Mode: 
  INFO = LAST = ERASE = ENTER Key
Checking for no Picture
A screen doesn't if display at all and condition of black pattern or power off.
(1) Check whether the CTRL B/D LED(D1~D4) is turned on or not.
(2) Check the power and signal cable of CTRL B/D.
(3) X B/D, Y B/D, Z B/D is well plugged in.
(4) Check the connection of X B/D, Y B/D and Z B/D to CTRL B/D.
(5) Measure the output wave of X, Y, Z B/D with oscilloscope(more than 200MHz) and find the trouble of B/D by comparing the output wave with below figure.
* Measure Point fo Y B/D : TP (Connector P4 80 pin)
* Measure Point fo Z B/D : Connection part of panel (SUS_OUT)
* Measure Point fo X B/D : L1(RIGHT), L2(LEFT BOTTOM)
(6) Check the SCAN(Y side) IC
(7) Check the DATA(X side) COF IC
(8) Replace the CTRL B/D.
4/7 or 3/7 of the screen doesn’t be shown
(1) Confirm the power connector of X B/D is well plugged in which is correspond to not showing screen.
(2) Confirm the connector that is connected between CTRL B/D and X B/D correspond to not showing part.
(3) Replace relevant X B/D.
The screen doesn’t be shown as Data COF
(Include not be shown part of Data COF quantity or a part)
(1) The problem between Data COF and X B/D is more possible that the screen is not be shown as data COF.
(2) Confirm the connector of Data COF is well connected to X B/D. Correspond to the part that screen is not showing
(3) Confirm whether the Data COF is failed and replace X B/D
How to check the Data COF IC [COF = Chip On Film]
Generates Unusual Pattern of Data COF IC unit
(1) In case of generating unusual pattern of Data COF IC unit as below picture, there is problem in the check that is input into Data COF IC
(2) In case of <case 1, 2, 3>
* confirm the connection of Data COF connector
* replace the relevant X B/D
(3) In case of <case 4, 5>
* confirm the connector that is connected from CTRL to X B/D
* Replace relevant XB/D or CTRL B/D
Regular Stripe [Line Fault] is Generated about the Quantity of one Data COF IC or more
(1) In case of generating regular stripe about the quantity of one Data COF IC, there is problem at the output of output flatworm of X B/D In case of generating regular stripe about the quantity of two Data COF IC, that means the data which is conveyed from CTRL B/D doesn’t conveyed well.
(2) Confirm the XB/D connection connector plugged in well. Correspond to unusual screen.
(3) Replace relevant XB/D or CTRL B/D.
Screen Display Form
The screen display has a problem for Scan FFC.
(1) It’s may be a problem between Scan FFC and Y B/D.
(2) Check the connection of Y B/D and Scan COF.
(3) If the Scan IC is failed, replace the Y DRV B/D.
How to check the SCAN IC
The screen has a vertical line with regular gap.  (A vertical stripe flash at especial colour)
(1) This is a problem about control B/D.
(2) Replace Control B/D.
Data copy is happened into vertical direction
(1) In this case, it’s due to incorrect marking of scan wave.
(2) Replace a Y DRV B/D or Y SUS B/D.
The screen has one or several vertical line
(1) In this case, It isn't a problem about controller B/D or X B/D.
(2) It may cause followings.
* It’s out of order a panel
* Open or short of DATA COF FPC attached panel
* It’s out of order a DATA COF attached panel
(3) Replace Module.
The screen has one or several horizontal line
(1) In this case, it isn’t a problem about controller B/D or X B/D.
(2) It may cause followings.
* It’s out of order a panel
* Open or short of SCAN FPC attached panel
* It’s out of order a SCAN IC attached panel
(3) Replace Y DRV B/D
The screen displays input signal pattern but the brightness is dark
(1) In this case, Z B/D operation isn't complete.
(2) Check the power cord of Z B/D.
(3) Check the connector of Z B/D and Controller B/D.
(4) Replace the Controller B/D or Z B/D.
The screen displays other colour partially on full white screen or happens discharge partially on full black screen.
(1) Check the declination of Y B/D set up, set down wave.
(2) Check the declination of Z B/D ¢«ramp wave.
(3) Measure each output wave with oscilloscope(more than 200MHz) and compare the data given below.  Adjust the Y B/D set up(Test-up:B/C[¥s/¥s])/set down(Test down: D[¥s]) and Z B/D
ramp(Tramp:F/G[¥s/¥s]) declination by changing VR1/VR2/VR3.
* Measuring Point of Y B/D : P4 (Connector P4 36 pin)
* Measuring Point of Z B/D : B37 (SUS_OUT)
Centre of screen is darker than a edge of screen at full white pattern.
(1) In this case, it’s a problem about Z B/D ramp wave.
(2) Check the connection cable of Z B/D and CTRL B/D.
(3) Replace the Z B/D.
Doesn't display a specified brightness at specified colour
(1) Check the connector of CTRL B/D input signal.
(2) Replace the CTRL B/D.
Proposed measures taken to relieve image sticking
  So long as there is the reduction of brightness in the fluorescent substance, it is impossible to the avoid the occurrence of image sticking .Therefore, to relieve image sticking,we offer you a method of entering an image input that may ensure reluctance to the generation of the difference in brightness reduction among the displayed dots.
  The images from TV broadcasting involve a high rate of motion picture displays. Therefore, there is less change of being a cause of difference in brightness reduction among the cells. Even when the fixed patterns are displayed, they generally last for a few minutes. Since the same pattern is less liable to be displayed, there is almost no influence toward image sticking.  If the fixed patterns tend to be displayed for a long time, however, there occurs a substantial imbalance between the lighting and non-lighting areas, this causing a difference in brightness as a result. In this document , we offer you some proposals of installation, paying attentions to the two points: the reduction of difference of brightness achieved by integrated lighting time levering and the method of edge smearing to make image sticking hard to be discerned.  The result from these proposals can, however, greatly depend on the contents of images and operating environment.  Therefore, we consider that it is essential to take the suitable measures in consideration of the customer’s operating environment.
Example of Proposal 1: The display position is moved while the fixed display pattern is changed over, or it is scrolled during the display.
Example of Proposal 2: If possible, a pattern of complementary color is incorporated (for integrated time levelling).
Example of Proposal 3: The fixed pattern and the motion picture display are reciprocally exchanged, in order to minimize display period of the fixed pattern.
Example of Proposal 4: During operation, the brightness of screen is suppressed as low as possible.  For the display patterns, characters are indicated not on the black ground (non-picture area) but on the coloured ground (mixture of R, G,B recommended).
Apart from the above proposal, some module has been equipped with a special method that minimizes the image sticking phenomenon. When in the fixed pattern display mode, the module decreases the brightness over a period of 10 minutes with small steps. The figure blow shows that the decrease in brightness is so small the user will not notice.  The basis of the evaluation was while the ISM Mode in the module was operating, the brightness decrease about 55 % of its initial value at the white window pattern ( 1/25 of full white pattern ) ISM operational conditions
1. Detective deviation: The change of APL Data is no less than ± 4 and it will remain for more than 5 minutes.
2. Regardless of time, it will not operate where the display load is over 50%.