Introduction: Test Tweezers for SMD-LEDs
I rarely work with SMD LEDs, but I quickly realized that's not easy, to find the polarity, and without putting them under power, you will never know the light color.
So I quickly built me this tester. It's just a CR2032 battery between two parts of wood or plastic. To conduct the electricity I took a self-adhesive copper tape.
Step 1: Quick Cad Draw
I use Qcad to draw the parts needed. I imported them to Inkscape to send the file to the laser cutter.
Nice clean parts, for a quick helping tool
Attached to this step the svg and dxf files
Step 2: The Parts
3mm - 3.5mm MDF or Plexiglas
three screws M3 12mm
three nuts M3
Self-adhesive copper tape
Adhesive tape
One CR2032 battery
Step 3: Mounting All Together
Cut 2 stripes of copper tape. As seen on the picture, make sure, that the tape does not cover the screw holes, otherwise you will get a short circuit.
Now remove the protective paper, and glue the copper on the inside of the two parts.
Use some tape to insulate the middle part of the copper. Do not cover the two extremities.
Take the three screws and pass them through and place the round part. Place the Battery (Check the polarity!)
With the 3 nuts, screw the last part of it and finished. As you can see, it does the job.
Step 4: More Than Expected
You can even check normal LEDs with this SMD-LED Tester. Not bad for a tool, developed and built in less than an hour.
Hopefully this instructables was useful.

Grand Prize in the
1 Hour Challenge
1 Person Made This Project!
- alanjperazzo made it!
13 Comments
3 years ago
Great idea. I would add an LED in series on one of the legs for when you short the ends together it won’t short out the battery and the LED can act as a power on indicator.
Reply 3 years ago
Wont work, voltage drop too high with LEDs in series for 3.7V battery.
Reply 3 years ago
I added a 100 Ohm SMD resistor (0603) in series. Most LEDs work with 1-20 mA and between 1.5V (red) to 3.2V (white). In the worst case, when both ends are occasionally shorted, this small resistance preventes a short-circuit, flowing only 3.0V / 100 Ohm = 0.03 = 30mA through the battery and contacts (battery = CR2032, which has about 3.0V with about 200mAh "power").
3 years ago
Finally, thank you very much. Great job !
3 years ago
What i sense just looking at the picture is: being speechless....
Take a bow, Sir.
3 years ago
Sir, you are a genius.
3 years ago
Nice one!
Tip 3 years ago
Hi, intresting Idea :3
Maybe build in simple circuit: additional taster powering a coil over transistor for having AC puls output for testing LED in booth ways have fun =^.^=
3 years ago
A simple and great idea
3 years ago
I feel a Resistance Soldering tweezer coming on . . .
Thanks for the inspiration.
3 years ago
Well done! What a great idea.
3 years ago
Ingenious, awesome and brilliantly simple - and it can also test any other LED.
3 years ago
What a clever but simple idea that will save me considerable frustration!