How To Check LED Bulbs Using A Digital Multimeter

Since the LED bulb is transparent, it is impossible to tell which of the chips have burned out on a visual level. This holds true for the other components. Use a multimeter, a tool for measuring current and resistance, to check an LED bulb. Additionally, you’ll need it to inspect the cable for breaks.

You should learn how to use a multimeter, learn how it works, and become familiar with the modes and usage guidelines if you want to find a fault. Multimeters come in analog and digital forms. Because the second version’s indicators for diagnosis are more precise, experts advise purchasing it.

A digital multimeter makes it easy to test LED lights and provides an exact measurement of each light’s intensity. The LED’s brightness when you test it will also show you how good it is. If you don’t have a multimeter, a simple coin cell battery holder with leads will test the functionality of your LED lights.

How to Check LED Bulbs Using a Digital Multimeter

Step 1: Buy a digital multimeter that can measure diodes

Simple multimeters only measure voltages, amps, and ohms. A multimeter with a diode setting is required to test LED lighting. Mid-range to high-range multimeters, which are more likely to offer this capability than affordable versions, can be found online or at your local hardware store

A good mid-range multimeter should run you $50 to $100 USD.

Choose a digital multimeter instead of an analog one, which will be less accurate and easier to misread.

Step 2: Hook up the red and black test leads

Connect the black and red test leads. To the outlets on the front of the multimeter, attach the red and black test leads. The positive charge is in the red lead. The input marked “COM” should be connected with the black lead, which is negative. Select the diode setting on the multimeter’s dial.

Step 3:Turn the multimeter dial to the diode setting

To move your multimeter’s front dial from the “off” position, turn it clockwise. Up till you reach the diode setting, keep turning it. The diode setting may be represented by the diode circuit symbol if it is not named explicitly.

  • The cathode and the anode of a diode are both visually represented by the diode symbol.

 Step 4:Connect the black probe to the cathode and the red probe to the anode

The red probe should be connected to the anode and the black probe to the cathode. The cathode end of the LED, which is typically the shorter prong, should be touched with the black probe. The red probe should then be pressed against the anode, which is the longer prong. Ensure that the black probe is connected before the red probe, because the reverse may not provide you with a reliable reading.

  • During this test, be sure the cathode and anode are not in contact with one another since this could prevent electricity from flowing through the LED light and affect your results.
  • Throughout the test, the red and black probes must not come into contact.
  • The LED should turn on after making the connections.

Step 5:Check the value on the multimeter’s digital display

Verify the reading on the digital multimeter display. A healthy LED light should show a voltage of about 1600 mV when the probes are in contact with the cathode and anode. If during the test there is no reading displayed on your screen, repeat the procedure to ensure that the connections were completed correctly.

  • If the exam was properly administered, this might indicate that the LED light isn’t functioning if the test was done correctly. You must replace the transformer if your supply does not produce any output voltage.
  • LED lights need to be replaced if there is voltage present at the output.

Read Also: how to find a short circuit with a multimeter

How to check without unsoldering the diode

A stylus is used to check the LEDs that are installed on the board. However, it’s possible that ordinary tools won’t fit through the transistor’s connector. Here, a thin conductor will be required. These include:

  • Sewing needles,
  • A length of cable or stranded wire, and office paper clips are examples of materials.
  • Office paper clips

The conductor will need to be attached without a plug by using an adapter or soldered to a foil stylus. If a foil plate with soldered wire fragments is used, it must be inserted into the correct multimeter slot, and probes constructed from the start must be utilized.

Conclusion

In conclusion, using a digital multimeter to check LED bulbs is a practical and straightforward process that allows you to quickly assess their functionality. By following the steps outlined in this guide and paying attention to the voltage readings on your multimeter, you can determine whether an LED bulb is operational or if there are issues that need further investigation.

Regularly checking LED bulbs using this method can help you identify problems early, ensure proper lighting in your applications, and avoid unnecessary replacements. Remember to prioritize safety by turning off the power before testing and handling electrical components, and if you encounter persistent issues, consult a professional for further assistance.

FAQs

What if I don’t get a reading on the multimeter?

If you don’t get a resistance reading, it could mean there’s no short circuit in the part of the circuit you’re testing. Move the probes to different points to continue your search.

How do I prepare to find a short circuit with a multimeter?

Before you start, ensure your multimeter is in working condition and you have a basic understanding of the circuit you’re testing. Always disconnect power sources to prevent electrical shocks.

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