How to Test a Capacitor with a Multimeter (5 Easy Methods)

If you want to learn how to test a capacitor with a multimeter, Follow this step-by-step guide to check and test for troubleshooting.

The multimeter work to determine the capacitance by charging the known current. That measures the resulting voltage for capacitance calculation. If you get confirmation that the capacitor is damaged, faulty, or leaked, It will replace a good one to repair the device.

Here are a few different methods to test a capacitor. At the end of this article, we can get the answers to the below questions:

  • How to Test a Capacitor With a Multimeter?
  • How To Use a Voltmeter to Test a Capacitor?
  • Traditional Method to Test Capacitors?

Warning: A capacitor may build up a dangerous residual charge. Before touching it or taking a measurement, Please ensure that you carefully discharge the capacitor by connecting a resistor across the leads. For Safe discharge, wear appropriate personal protective equipment recommended before any testing.

How to Test a Capacitor with a Multimeter

How do you test a capacitor by Multimeter? This method is used for finding the faulty capacitor by measuring the capacitance, Resistance, or potential difference across the capacitor. We will explain in detail how to measure capacitors to a Multimeter here.

Using a Digital Multimeter With Capacitance Setting

Here’s my favorite and familiar way of testing a capacitor with the help of a digital multimeter. It is also a straightforward and easiest method of capacitor verification.

Testing capacitors with a digitalIn modern digital multimeter, you can find a capacitance meter and a voltage meter. Similarly, this method works on tiny SMD components as well. The following instructions demonstrate using your digital multimeter to test an AC capacitor.

  1. Be sure to remove the capacitor from the circuit and fully discharge it before measuring its value.
  2. In Multimer, the capacitance value is displayed in Farads as the farad is normally expressed in microfarads (F).
  3. Turn the knob on your multimeter to “capacitance” mode.
  4. Connect the multimeter probe to the capacitor terminals. In polarization, connect the positive terminal to a red multimeter probe and the negative terminal to a black probe.
  5. Write down the actual reading after checking the multimeter on paper. 
  6. The capacitor needs to be replaced if the printed reading and measured reading are significantly different or if both readings are zero.

It is this way that one can determine if a capacitor is bad. If the capacitor is faulty, you can replace and troubleshoot your electronic device. This is a straightforward and standard method of testing a capacitor with a digital multimeter.

How to test a capacitor
Fig -Demonstration of how to test ac capacitor with a digital multimeter

Using a Digital Multimeter With Resistance Setting

Several Digital Multimeters do not include a capacitance feature, so the above method is not applicable, but we can still test the capacitor by measuring its resistance.

Step by step instructions on testing a capacitor with a multimeter by measuring its resistance

  1. Remove the capacitor from its circuit and make sure it is fully discharged.
  2. Set the Multimeter knob to Ohm (unit of Resistance) or the Greek letter omega (*), as shown in Figure 1.
  3. Connect the multimeter leads to the capacitor terminals again, ensuring that the red one is on the positive and the black one is on the negative.
  4. The first resistance reading that appears on display should be noted. Within a few seconds, it sets to display a value of infinity (Open).
  5. Disconnect the probes and respect them repeatedly. This indicates that the capacitor is in good working order if the results are the same as before.
  6. The capacitor is faulty (dead) if it doesn’t change in any of the repeated tests.
How to Test a Capacitor with a Multimeter

3. How to test capacitor using analog multimeter

By using other parameters, such as current (A), voltage (V), and resistance (O), we can test the capacitor just like we can with digital multimeters. This section explains how to try the capacitor with a resistance measurement—this step-by-step guide on testing a capacitor with a simple analog multimeter.

  • Follow the same steps again: remove the capacitor from its circuit and inspect it for full discharge.
  • Make sure your multimeter is set to its resistance setting (Ohmmeter *) and select the higher range.
  • The red probe should go on the positive terminal, while the black probe should go on the negative. 
  • The needle pointer on the display of an analog multimeter measures the reading and the position of the needle determines the capacitance result.
  • It indicates that the capacitor is functioning properly if the needle initially displays a low value and then moves to the right side and displays a higher value after some time.
  • When the needle initially shows a low value and does not move further, it indicates a faulty capacitor.
  • It is possible that the needle in the third case shows no resistance value or does not move for any value. This indicates that the capacitor is open and faulty.
Testing a Capacitor With a Voltmeter

4. How to test a capacitor with a digital multimeter


To check whether a capacitor is defective or not, we will use a simple voltmeter to measure its voltage rating. You can follow these steps to test a capacitor with a voltmeter in the following section: Testing a Capacitor With a Voltmeter.

  • After a fully discharged capacitor, desolder it and remove it from the circuit. For measurement, you can also remove one lag.
  • The capacitor’s voltage rating should be written on a piece of paper on the meter and checked outside of the capacitor body. You can find the number after the capital “V” on any body part. For example, 16V,50V, or another value.
  • The capacitor needs to be charged with a voltage less than its rating. If the capacitor’s rated voltage is 30 V, charge it with 9 V and charge it with 600 V at least.
  • Ensure the positive terminal is connected to the red probe and the negative terminal to the black probe. 
  • Connect the red probe to the positive terminal and connect the black probe to the negative terminal of your voltmeter. Now you’re ready to measure the voltage of the charged capacitor. 
  • A capacitor that measures close to its rated value is good. The capacitor is faulty if the voltage gap is higher.

Traditional Method to Test Capacitors

This method was more popular in the old days, as it did not require any measuring devices for validation. This article will discuss how to test a capacitor without a multimeter.

While this method is risky and not recommended by professionals, safety precautions should be taken if it is necessary. Protective gloves should be worn, and metal surfaces should not be touched. Following is a step-by-step guide on shorting the capacitor terminal to test a capacitor. The following steps are involved in testing a capacitor. Again, the question is the same: how to try the capacitor without desoldering the component and possible.

  • Remove the capacitor from the circuit board by de-soldering, and the capacitor must be discharged completely. 
  • For one to four seconds, connect red to the positive terminal and black to the negative terminal of the power supply.
  • Short the capacitors to a metallic wire or rod as a safety precaution.
  • A spark’s intensity can be used to determine the charging capacity of a capacitor. The capacitor is in good condition if the spark is strong and long. Otherwise, the capacitor is faulty.

How to test a capacitor with a multimeter in a circuit

Another question is testing the capacitor without desoldering or removing the capacitor from the circuit board.

When a capacitor is mounted On the circuit board, measuring the actual rated value through the multimeter or capacitance meter is impossible because several other components are placed on the same circuit board. Due to that capacitor gets an equivalent value rather than the actual.

The question is the same: how to test the capacitor without desoldering the component and possible.

Yes, it is possible by using an equivalent series resistance (ESR) meter or smart tweezers both work fine, but the ESR meter is more suitable for through-hole components and smart tweezers for tiny SMD components. How to test capacitor without Desoldering Below 3 methods to identify the faulty capacitor.

1. Test a capacitor with ESR Meter

The ESR meter device is used to determine the equivalent series resistance without desoldering or removing it from the circuit board. This device can not measure the capacitance but can test the capacitor. You Can Buy online (ESR meter (Amazon Link).

 Below are the steps that need to be followed to test capacitor insight into the circuit.

  • To test the capacitor first and essential step is to discharge the capacitor completely. To discharge, you can short the capacitor terminal with the help of metallic items.
  • Turn on the ESR meter and contact the red leg with the capacitor positive terminal and black with the negative terminal. And short its leads till display zero reading.
  • Note the reading of the ESR meter and note it down.
  • Now compare the noted table reading on the body of the ESR meter. If the gap is within range, the capacitor is OK, and there is no need to change.
  • ESR is not giving any table. You can check with a capacitor datasheet and compare it with the measured value.

2. Smart Tweezers

Smart Tweezers are more handy and Portable to do jobs more fun and comfortable.ESR Meter is not more reliable in dealing with the tiny SMD component.

But the drawback of smart tweezers is that they are too costly. Otherwise, they work very smart and effectively. (Smart Tweezer (Amazon link)

Visual inspection for Bad Capacitor

Sometimes, you can quickly check the capacitor by visual inception rather than smart tweezers or ESR meters.

A faulty capacitor gets swallowed on the top side and gets some damage or burnt remarks on the body. If you find such observations during inspection, replace the suspected capacitor for fresh.

What is a capacitor?

A capacitor is an electrical component that stores energy as an electric charge and is often found in electronic appliances like air conditioning fans and compressors to perform various functions. The component is a passive electronic device with two terminals.  

Further, these capacitors can be divided into two types: Electrolytics, associated mainly with vacuum and transistor power supplies, and Non-Electrolytics, compatible with direct current regulation. The capacitor is known initially and widely famous as a condenser. The effect of a capacitor is known as capacitance.

If we talk about practical capacitors, the capacitor is mainly made of two electrical conductors plates septated by a dielectric medium. A potential difference between two conductor plates while connected across a battery results in positive and negative charges on terminals.

What are the safety precautions of testing capacitors

Testing capacitors is a common task for electronic technicians. There are a few safety precautions that must be followed when testing capacitors. First, always use safety goggles when testing capacitors. Second, use a multimeter with the proper voltage range to test capacitors.

Third, make sure that the capacitor is connected in the correct way to the multimeter. Fourth, do not exceed the maximum voltage rating of the capacitor. Finally, never use an excessive amount of force when testing capacitors.

Conclusion – Wrapping it up

Testing capacitors is an important part of ensuring they are functioning correctly. There are a few different ways to test a capacitor, and each has its own advantages and disadvantages. One way to test a capacitor is to use a multimeter. This article describes how to test a capacitor using a multimeter.

With this information, you will be able to answer the question of how to test a capacitor with a multimeter in both conditions: without removing it from the circuit board and with it attached to the circuit board. Also, how to check capacitors without a multimeter.

You can identify faulty capacitors with digital multimeters, ESR meters, and intelligent tweezers. A multimeter is used to measure the ESR of a capacitor in a circuit, and smart tweezers are used for capacitor inspection.

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Hello, this is Manoj, A Soldering and DIY Tool expert. Writing is one of my hobbies. With more than 20 years of broad experience. I love researching, discovering, and sharing new products with others, I hope you’ll enjoy the greatest featured products to make life easier, more fun, and more productive.

3 thoughts on “How to Test a Capacitor with a Multimeter (5 Easy Methods)”

  1. What about also bypassing a cap? I’m thinking more about an audio circuit amplifier. I have some powered monitors that one of them is not producing any sound. I was taking about injecting a signal on input, and then jumpering (with it without a similar capacitor) to see if sound comes out then.

    Also wondering, I know in the circuit an ohm meter is not so useful, but I’m thinking more if a go/no go test. I don’t at this point need to know if the capacitor has the exact correct capacitance, just if it seems to be not open. In circuit for example (I don’t have a schematic) I tried checking the two leads on three electrolytic capacitors that are bunched together, two fo them when I put the leads of the ohmmeter on it, react as expected, the third one though, never charges up or dissipates. Am thinking this might be a bad one but am not sure about the other components that might be making this one react differently to the same process, any thoughts?

    Reply

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