The most likely cause is that the polarity is reversed. A LED backlight operates on DC (Direct Current). The backlight must be connected correctly. The positive side of the backlight must be connected to the positive side of the power supply.
The positive side is called “A”. The other connection is called “K”, this is normally ground. If the polarity is reversed then the backlight will not work. The solution is to reverse the polarity. How?
LCD’s that come with the LED backlight integrated into the display normally have pin 15 set as positive and pin 16 as ground. Please see diagram below.
Your product may require pin 15 to be ground and pin 16 to be positive. If this is the case there are two jumper settings on the back of the LCD that allow the user to reverse the polarity.
Please contact us for information on which jumper settings to reverse the polarity.
Focus Display Solutions ® © 2010 Focus Display Solutions
