Keyboard backlighting is available only on some laptop models. Without a doubt, this is a very convenient option that allows you to work comfortably even in complete darkness. If you have a backlight, you need to know how to turn it on.
Instructions
Step 1
The keyboard backlight turns on when you press the Fn key and one of the additional keys. Which key to turn on depends on the laptop model.
Step 2
In many cases, the required key combination can be determined visually, since on the additional keys (the F1 – F12 row is used), manufacturers put additional characters. The color of these characters is the same as the label on the Fn key. Experiment by pressing the extension keys with Fn. Look for a graphic with a backlit keyboard symbol.
Step 3
Please note that when you press the keys, you can use other options - turn off the screen, enter sleep mode, etc. To undo your changes, press the same key combination again.
Step 4
If the drawings on the keys did not allow you to identify the desired combination, while you know for sure that the keyboard backlight on your laptop is, try the following combinations:
- Fn + F6 or Fn + right arrow;
- Fn + SPACE (space);
- Fn + F5.
Step 5
In the event that your laptop does not have a keyboard backlight, you can make an external backlight yourself using +5 V power from the USB connector and one or more white LEDs. In the connector, you need the two outermost pins (left and right). The supply voltage of the white LED is 3.5 V. This means that a resistor is needed on which the extra 1.5 V will be extinguished. The LED current is 20 mA, or 0.02 A. Then the resistance of the additional resistor will be 1.5 V / 0.02 = 75 Ohm.
Step 6
If the brightness of one LED is not enough, connect another one with the same resistor in parallel. Be sure to check the current consumption of the LEDs, as its difference from 18-20 mA negatively affects the life of the LED. Set the required current by selecting a resistor. The USB connector is capable of delivering up to 0.5 A, which means that up to 25 LEDs can be powered from it.
