I bought Yamakasi 2703 display from greensum in late summer. It was ok for a while but then the left side of the display started to be dimmer than the right side. Because I live in Finland I thought that warranty was not an option. It would cost too much to send the unit back to Korea. Not to mention that I had disposed the cardboard-box of the display that greensum wanted to have if returned...
Now, after too many months of seeing the dark side of the screen, I decided to open up the display to see what is wrong.How to open:
Place the display face down to a table. Remove the screws from the backside. Turn the unit display up and take the bezel off by turning a flat screw driver between the bezel and backside plastic.
The LCD panel is attached to the backcover with some screws on both sides. Take the screws off and turn the unit panel down again. Be careful, the panel is not attached to the plastic anymore. Rise the backplastic carefully to view the cables inside.
Take off some of the aluminium-tape covering the shortest display cable. Unplug the cable from the panel side.
You may also unplug other cables, such as keys-cable, led-backlight-cable and LCD-panel power cable. Now the backplastic is no longer connected to the panel and you can separete them.
The one and only PCB is under the flimsy metal cover in the backcover. Remove some screws and lift the metal cover. Now you can see the PCB.
The PCB looks OK. No darkness around the transistors as in some of the Crossover displays with backlight problems.
Remove the four screws to remove the PCB. On the backside of the PCB you can see something strange.
AT first I of course thought that this has something to do with the backlight problem. The jumper cable was connected to the pins for the cable of the fully functional side of the LED-backlight. As it turns out this has nothing to do with the backlight problem. Most likely the PCB had a bug when it was ordered and they fixed it with this jumper cable.
I set the display so that I could use it so see what affects the backlight. As you can see from the video below, the white led-backlight power cable was the cause of the problems. (It´s safe to do this as the voltage of the led-backlight is only about 30V or more, opposed to CCFL backlights with many thousands of volts. Also the voltage coming to the PCB is only 24V.https://www.youtube.com/watch?v=iZWoNwn1po4
I removed the white backlight power cable and removed the black tape covering the connector. I saw a poor adapter that was glued to the cable. The adapter is used to change the female connector to male, so that it can be connected to the panel side of the backlight cable which is also female. The connection between the cable connector and the adapter is very loose and poor.
In the picture I have removed the adapter.
I made a drastic decision and removed both of the plastic parts of the connector and the adapter (seen in the picture above).
I soldered the connector spikes directly to each of the display cable lines.
I put some tape around the metal parts of each cable to provide insulation as each cable is almost touching the closest ones. Only the spike was left exposed . Then I put each of the cables in to the panel side of the led-backlight cable connector.
Now the backlight is fixed.Edited by Astire - 1/12/13 at 6:32am