backlight burnt ?

Hello ! I just received my LCD. Except I think I burnt the backlight =( ... I dare not do anything and I'd like your opinion. I connect the 5V and Ground pin A on K. The screen is lit then immediately éteinds. I make a fatal mistake? If yes, which one? Thanks.

If the LCD module doesn't have a current limiting resistor built into it, you might be drawing enough current to shutdown whatever you're using as your power supply.

So what can I do :~ ?

The backlight is most commonly an array of LED's. They almost never have current limiting resistor. Failure to add one can cause failure of the LED ARRAY.

There is no telling anything unless you tell us what make and model display you have. (eventually also where you got it) We can only guess unless you tell us more.

Here is the datasheet :

Your answer is on page 3 of the datasheet. What color is the backlight ?

Most of the colors have a typical current of 20 mA and max of 25 mA. White, green and blue have typical 3.4 volts and 3.5 volts max (that's tight). Amber has 1.8 volts and 1.9 volts max.

This all means there is no current limiting in the display and you'd have to create that yourself. You did not, and most likely blew it up.

You should always read the datasheet. If you don't understand what it's telling you, ask. Just to try something, will moast likely end up in tears.

Must be taken to be learned =(
Now I’ll read the datasheet ! Thank you for answers !