- Check to see if the power supply plug from the power filter board to the power supply board is well inserted into the socket. If not, plug it in.
- Check if the fuse on the power supply board is blown up. If yes, replace it for a good one.
- Remove our main board and the video frequency processing board, ground the pin 4 POWER_ON/OFF of socket CN802 of the power supply board, and then push the slide switch SW2001 on the logic board to the internal modes (1, 3 up and 2, 4 down) from external modes (1, 2, 4 up and 3down).
- Switch the power on and see if the screen is lit. If the screen can give a normal and completely white field signal, then the problem lies in our main board or video frequency processing board, which will be dealt with separately.
- If the screen is not lit, then first replace the power supply board to see if the problem is solved.
- If the problem remains after the power supply board is replaced, then the problem lies in the screen. Replace the entire screen for treatment.
LINE OF SEVERAL UNLIT LINES
- Check if the socket between Y driving board and Y BUFFER is plugged well. If not, plug it well. If yes then replace Y BUFFER (upper, lower) in respect to the upper , lower part of the dark line on the screen.
- Check if the socket between Y driving board and Y BUFFER is plugged well. If not, plug it well. If yes then replace Y BUFFER (upper, lower) in respect to the upper , lower part of the dark line on the screen.
One vertical unlit line or a vertical entirely unlit block.
- If it’s one vertical unlit line, then COF has problem. If it’s a vertical entirely unlit block, then first check if the connection socket between COF and logic BUFFER has problem. If not, check if the connection sockets between the logic BUFFER and the logic board is normal. If yes, replace the logic BUFFER. Finally, if the problem still remains when the replacement is over, then replace the logic board.
- If it’s a vertical bright line of other colors, then the problem lies with COF or the screen.
- If it’s an entire vertical block of other colors, then first check to see if the connection socket between COF and logic BUFFER has problem. If no problem, check if the connection sockets between the logic BUFFER and the logic board is normal. If it’s normal, then replace the logic BUFFER. If the problem still remains after the replacement, then replace the logic board. Finally if the problem is still there, then the problem lies with COF.
- Check if the connection socket between COF and logic BUFFER board has been well plugged.
- Replace the logic BUFFER board. If it’s not solved then replace logic board. If the problem still remains, then it’s the problem with COF.
DEBUGGING
For Models PS-42D8 and PH-50D8, the debugging part lies only in the white balance adjustment. Nothing else should be adjusted and the maintenance software supplied for after-sale purpose has normally shielded the value of white balance i.e., no more adjustment is needed when upgrading the software. In case of special circumstances where the main board is replaced following method can be adopted:- The white balance adjustment is made respectively in three ways - TV/AV, VGA,YpbPr. First adjust TV/AV, then VGA and YpbPr at the last
- Select corresponding channels respectively. After successively press the keys on the production plant’s remote control (the key at the right hand lower corner doesn’t show up), go on to press the left key, right key, confirmation key on the small keyboard one by one and then it’s possible to enter the menu set up in the plant.
- Use the right key to select and calibrate the menu. The white balance adjustment and YpbPr white balance adjustment are for the purpose of white balance adjustment. For the white balance adjustment of TV/AV and VGA it’s OK just directly adjust the first item whereas for YpbPr adjust the second item.
- For the white balance adjustment of TV/AV and VGA: select the item of “white balance adjustment” from the menu. When it’s entered, keep RCUI immovable and adjust GCUT and BCUT so as to adjust the white balance of the dark area. For the adjustment of white balance of the bright area, keep RGR immovable and then adjust GGRV and BGRV. Repeat the above steps several times until the picture is normal in white balance. For the white balance adjustment of YpbPr: select the item of “white balance adjustment” from the menu. When it’s entered, adjust RCUT, BCUT and it’s done.
SOFTWARE UPGRADING
- Select a connection wire of serial port, which is required to have a notch on its both ends, and also the pins 2 and 3 on the two ends are cross connected.
- Use the serial port connection wire to connect PC with PDP and set PDP to the off position.
- Open the folder of the upgrading software and double click the FlashUpgraderNT (on condition of window 2000/XP/NT)
- Based on the features of computer set up the serial port (COM Port) and select corresponding serial port (if it’s not possible to burnt-write other serial port can be used instead).
- Baud-select 115200 and then select Reset Target After Download. Hit flash press button and it’s ready to operate. For the setup of other items please refer to the figure above (already defaulted by the system so it’s normally unnecessary to alter).
- Switch on PDP and it begins to run the burnt-write program.
- Once it’s over with burnt-write, the cancel push button will become flash. Switch off the main power and then to switch on the TV set again.
