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We get it asked — a lot. Can I use a cheap multimeter to test a capacitor? Yes! If you want to learn how to test a capacitor with a multimeter, you can use your regular meter.
Generally, you would need a fancy and expensive meter meant for testing capacitance, but you can still use a cheap multimeter to determine whether your capacitor is working or not. While this is not the most accurate test on earth, it’s more than enough for most DIYers.
How to Test a Capacitor Using a Regular Multimeter
Using a multimeter is one of the easiest ways to test a capacitor. But beware, things can get out of hand if you don’t know what you’re doing. So, here’s how to test a run capacitor with a multimeter:
Capacitors store enough power to knock you out, so discharge it before moving any further.
That said, get a resistor and connect it to the terminals on top of the capacitor. The capacitor will now release all its energy onto the resistor, dropping the power immediately.
Avoid using a screwdriver for this job. It will damage both your tool and the capacitor. Furthermore, it is incredibly dangerous if you do not know what you are doing. If the capacitor is not safe to touch, get in touch with a certified professional.
2. Set Up your Multimeter
After discharging the capacitor, take your black lead and insert it into the COM hole. Next, grab the red lead and connect it to the VΩ hole. After that, turn the wheel to 200k ohms.
3. How to Test Capacitor with a Digital Multimeter
To start, put the red lead on the positive terminal and the black one on the negative terminal. The ohms will now increase until it reaches 200k. After that, the multimeter will display “1,” indicating there’s no more resistance to check.
If you want to test it the other way around, put the black lead on the positive terminal, and the red one on the negative terminal. The ohms will now go down, and then the numbers will increase, indicating that you’re charging it back up again.
With all this information, we can safely assume that your capacitor is working. However, this test does not tell us what kind of capacity it has. Instead, it’s telling us that it’s taking charge like it’s supposed to.
For more information about capacitors and how you can discharge them, watch this video:
How to Check Capacitors in Circuit Using a Multimeter
Testing a TV power supply is super easy and barely takes any time. But you need to know a few things to get this job done. So, here’s how to test a capacitor with a multimeter:
1. Discharge the Capacitor
As always, discharge your capacitor. A fully charged capacitor can cause severe damage in a matter of seconds. Even small capacitors can cause permanent damage and kill you.
As a side note, pay attention to the labels on the capacitors to know the voltage.
If you don’t feel comfortable discharging a capacitor, please get in touch with a professional — especially if you’re dealing with a capacitor that is not safe to touch.
2. Set the Multimeter to Farads
Capacitors are measured in farads, meaning you have to set your multimeter to farads. However, your multimeter will display different values depending on the brand. Here’s a list of some of the most common values:
- μF — microfarads
- nF — nanofarads
- pF — picofarads
All these values serve the same purpose, so don’t worry if you’re getting a different value.
3. How to Test a Capacitor with Multimeter in a Circuit
Put the black lead on the negative side and the red one on the positive side. The reading on your multimeter should be similar to the value on your capacitor. If you’re getting 10% lower than the actual value your capacitor indicates, replace it.
For instance, if your capacitor says 680UF, and you’re getting 274UF, it means the unit is not working and must be replaced. If you need more help getting through these steps, refer to this YouTube video:
Frequently Asked Questions ( FAQs )
Need more help figuring out how to test a capacitor? Then make sure to check this section out:
How to tell if a capacitor is bad?
- First, look for damage. For example, a faulty capacity looks ugly, has bubbles, and feels bulky. Furthermore, the bottom side might be bowed out. Still, run a little test using a multimeter to make sure the unit stopped working.
How do I test a capacitor with a digital multimeter?
- First, grab your two leads and put the positive on the positive terminal and the negative lead on the negative terminal. Next, set the multimeter to ohms. The numbers on the screen will increase until it reaches an open circuit, indicating the capacitor is still working.
What if a capacitor reads high?
- If you’re using a capacitance tester, please note that a lower number means your capacitor is still in great shape, but a higher number indicates that the unit has failed and must be replaced.
What is the capacitor symbol on a multimeter?
- A regular multimeter cannot be used to test capacitance. So, there’s no capacitor icon for that. Instead, turn the wheel to ohms, and you should be able to test a damaged capacitor.
Understanding how to test a capacitor with a multimeter is pretty simple and more manageable than testing voltage.
But even then, you should be careful when testing a capacitor. You will burn your fingers and feel the spark hit your heart from the inside.
Furthermore, you’ll blow the multimeter as soon as you put the leads on the terminal. So, stay safe and follow our steps carefully. Once again, if you don’t feel comfortable, call your local electrician.