Introduction: USB Powered LED Monitor Backlight (under £3)

This idea came about when I saw sets of red LED Christmas lights in the poundshop

Step 1: Tools and Equipment

2x LED Christmas lights in colour of your choice (must be 3 volt ones i.e. 2x AA battery) COST: 2x £1
A USB cable or something to rip one out of (e.g. an old mouse) COST: free to £1

Two colours of insulating tape (ideally red and black)
Duct tape (to attach lights to monitor)
Wire cutter / stripper
Needle file (or Dremel with appropriate bits)

For a neater and easier job:
Soldering iron + solder
Heat-shrink sleeving
Multimeter (to test polarity of LED strands and USB cable)
USB wall-wart type adapter (for testing, means you don't risk damage to your PC if you do something wrong)

Step 2: Dismantle & Prepare

Dismantle both sets of LED Christmas lights by removing all screws and either unsoldering the conections or cutting them. Take careful note of the polarity of the LED strands (mark with coloured insulating tape). We will be using both stands of lights, one switch and one battery box.

Many sets of lights include a small resistor if your's do save those as well.

Cut the USB cable to length and expose about and inch of the internal wires, we will be using the red and black wires (positive and ground) the green and white (data wires) should be trimmed back and capped with tape or heat-shrink tube.

Step 3: Make Your Circuit

Build the circuit as shown in the diagram.

Join together everything apart from the USB connector (make sure the two strands of lights are the same way around otherwise it won't work) if you do not have resistors with your lights then these should be omitted from the diagram.

Plug your USB cable into the USB wall adapter and check polarity of the connections before joining to the LEDs

Make the final connections and test (ideally with the wall adapter)

Cover all connections with tape or heat-shrink tube.

Step 4: Fit Items Into One of the Battery Boxes

Test fit all items into one of the battery boxes and attempt to fit the lids on, mark where wires naturally want to pass through the plastic then remove the circuit from the box and cut out these areas using a needle file or a Dremel.

Put everything into the box again and screw both covers on.

Test using the USB wall adapter.

Step 5: DONE

Attach the lights to the back of your screen(s) using duct tape, make sure not to block any vent holes that may be in the back of the screen.

Plug the cable into a spare USB port and boot up your PC.

The lights will come on as your PC boots and turn off when it does.

Hope you like this if you did please vote for me in the "make it glow" contest