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How to Test Circuit Board with Multimeter?

We can never deny the importance of PCBs in our daily lives. From microwaves to washing machines, almost all consumer electronics include PCBs in their construction. Due to this reason, it is important that we understand the significance and functioning of PCBs to avoid facing complications.

If you are into PCBs, you already know that PCB inspection is highly crucial. Due to this reason, we are able to experience precision PCBs in our day-to-day house chores. There are different methods by which we can inspect a PCB. However, experts recommend relying on the multimeter.

A multimeter is a good device to inspect your PCBs to find out any defects and faults in them. We are going to have a detailed look at the usage of multimeters for the inspection of PCBs. With a multimeter, you can not only inspect the entire boards, but you can individually inspect the PCB components. Therefore are different small-to-big components in a PCB that need an in-depth inspection.

However, since the multimeter is our topic of discussion today, you should know that there are different inspecting methods that most producers use other than this. These are all reliable. However, their costs are different. Due to this reason, different producers are more likely to opt for different PCB testing methods. The common methods are:

  • AOI PCB testing free/paid
  • X-ray testing 
  • Function testing
  • Visual inspection 

It is important to know that some PCB providers also offer efficient and fully assembled PCBs along with the inspection. Therefore it depends on your situation. You can still find some producers that offer these boards at affordable prices to make them more accessible. The shipping time also varies from one producer to the other.

Sometimes they can even expedite the delivery process for you in case you are dealing with a shortage or emergency. There are also different PCB makers who specialize in different types of PCBs, from complex to simple. RayPCB is one of the best PCB professionals that you can find online. They are exceptional in their services and products. Besides, they showcase an impressive clientele due to their fine performance at the same time. Annually, several partners collaborate with RayPCB to gain from their services.

You can rely on RayPCB for their shipping service and prompt delivery. They are continuously making improvements in their services to meet the requirements of their customers. Plus, they are also introducing the latest services like CNC machining and 3D printing to attract more clients. Their solutions for technological problems and prototyping are also reliable for collaborations. 

What is a multimeter?

Test Circuit Board
Test Circuit Board

A multimeter is basically a PCB inspection device. The purpose of a multimeter is to detect faults in the performance of a PCB. It measures voltage, current, and resistance in PCBs to find if everything is going okay or not.

Plus, you need to carefully connect the multimeter with your PCBs to get accurate readings. A controller is present on all multimeters, which helps you get precise readings from PCBs. Today, you can rely on a digital multimeter to ensure more accuracy, and it is also easy to use. 

How to measure voltage?

Voltage means the difference between the electric potential of two points present in a PCB. These points can be anywhere in the PCB. We denote voltage with a capital V in physics. To get the accurate voltage, you need to connect it to the PCB through its terminals. These are pretty obvious, and you won’t find any problem in joining them. However, there are some rules. Join the red probe with the positive terminal, and the black one is for the negative one.

Some people mix these up, and due to this reason, they end up getting inaccurate readings. So make sure to avoid this on all counts. After joining the probes with terminals, it is time to get to the dial. Switch it to voltage mode because we want to get the voltage. Make sure that the voltage you are setting on the multimeter should be greater than the voltage of the source. A 20V is enough for measuring the voltage of a 9V source. 

How to measure continuity?

Continuity means how much electricity a circuit like PCB can conduct on average, with the help of a multimeter to measure the connectivity of a device as well. We take this in Ohms. In this case, the process is different from measuring a PCB voltage.

Now, the first thing you need to do is to detach the power source. After this, you need to connect the multimeter to the device you want to measure the continuity of. Unlike with the voltage case, you can connect the probes with any of the terminals. Switch the multimeter to the continuity mode before proceeding. It will show the precise continuity on the screen for you.

Testing a Circuit Board That is not Functional or Working

·       Visual Inspection

You might often have faced that the PCBs undergo failure or suddenly stop working. It can happen to other types of circuits as well. In this case, you can find out the culprit easily using some methods. The best way is to manually inspect your PCBs.

So that you can quickly identify the defects with the naked eye, there can be reasons that a PCB can stop working all of a sudden. Problems with wiring, electrical complications, or heat damage can be possible problems. Let’s check out effective solutions for this problem:

·       Checking Power Module

The first thing you should consider is the power module. If you have manually inspected the circuit board, and there is no problem with the components, then the power module can be our culprit. Make sure to charge the power module fully. Make sure to take voltage readings through a multimeter to be hundred percent sure.


If the input and output values are accurate, then the circuit board is working fine. Sometimes the PCB components can undergo damage and start consuming extra current, which leads to further complications as well. Therefore checking the fuse also comes in handy. It should never. Show the value 0V because it indicates the short circuit of one or more components. Short circuits often heat up the entire board, and sensitive components get molten and completely ruined. In this case, you need to immediately separate the damaged parts and consider replacements to save your PCBs from possible failure. If overheating is not the problem, then traces can be damaged and make the PCB stop working.

·       Checking the Input or Output Ports

When considering the PCB culprits, the input/output ports play a huge role. Damaged I/O ports mean these will hamper the fine performance of PCBs. These ports have the potential to turn off the entire circuit in some cases.

Due to this reason, maintenance of these orts is important to save your circuits. If there is no problem with the I/O ports, then issues with the microcontroller can arise such problems. 

·       Checking Communication Ports

Circuit boards with communication ports can also undergo abrupt shutting down. Therefore the inspection of communication ports is important. Problems in communication can lead to heat damage and defective communication among the circuit components.

You need to make sure that the ports are working fine, or in the other case, you can ask for help. It is because there have been many cases reported that indicated problems with the communication ports led to the shutting down of circuits. 

·       Optimize Printed Circuit Boards for Troubleshooting

Circuit board testing is a crucial process to ensure PCBs are safe to use. Defective PCBs can not only give shocks, but they can easily catch electrical fires. Not only this, a faulty PCB can ruin the entire electronic device. Therefore, an in-depth and rigorous inspection of PCBs is not only crucial, but it ensures that the PCBs meet industrial standards.

For example, using a multimeter gives you a wide range of inspection options. You can take readings for the voltage, continuity, resistance, and current as well. Some users can do it manually. However, if you don’t know the method, it is better to take professional help. Plus, you can find and hire professionals for the sake of PCB inspection. In this case, you will have more guarantees that your PCBs are just fine and will serve longer. 


Now you know that PCB producers cannot ignore inspecting their PCBs before delivering them to you. It is because defective PCBs not only invite more damage. But these can be unsafe to use for the users.

Due to this reason, we have discussed a multimeter for detecting PCBs. You can easily choose one inspection method and see if it fits your budget or not. In other cases, you can seek professional PCB inspection services from the providers. However, keep in mind that these services vary in terms of pricing as well.

Therefore, always consult the PCB makers for inspection services before you proceed with them. It will not only save you from loss of money and time, but it will ensure your safety too. 




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