Common breadboard mistakes

If your breadboard circuit doesn’t work don’t worry you are not the first and won’t be the last. Fortunately, there are a lot of common breadboard mistakes that people can make.

Work through these and you’ll hopefully find the one you’ve made and you can correct it to get your circuit working.

Common breadboard mistakes The breadboard

A wire or component has become unplugged

A common problem is that a component lead or wire has become unplugged. The solderless breadboard will only hold the component in place until it’s pulled out and it doesn’t take much force to pull out a lead.

It’s very easy to accidentally pull a lead out if you knock it while trying to put in another component or connection or if you’re trying to bend a lead to get it to fit in the correct hole.

Make sure you use the correct breadboard wires in the first place.

This is one of the most common breadboard mistakes.

Have a close look just to check that nothing has fallen out.

Learn the resistor colour code

It’s not hard and once you know it you’ll save so much time.

You plugged it in the wrong hole

As I mentioned it’s easy for a wire or component to come out. If that happened while you were building your circuit you did put it back in the right hole, didn’t you?

While we’re talking about replacing things in the right hole it’s very easy to put them in the wrong hole to begin with. Go through the circuit and check you’ve got things in the correct row.

Component the wrong way round

Did you plug the IC in the correct way around? Everyone plugs one in wrong every now and again. And while you’re checking the direction of the IC’s face, check for the other polarised components.

Transistors, capacitors, diodes and LEDs, make sure they are all oriented the right way around.

The component is not pushed in enough

Make sure the components are properly plugged in. Sometimes they are in the correct holes but not quite plugged in enough. Give them a bit of a push to check they are making electrical connections.

While on the subject of electrical connections, sometimes the spring action of solderless breadboards starts to loosen, especially if you’ve had a component plugged in with a thick lead and you put a thin leaded component in the same place so have a look at the components with thin leads.

That’s some of the newer small resistors and diodes like 1N41418. They seem to have thinner legs than most.

Common breadboard mistake – Power the wrong way round

Check that the power is the correct voltage and correct polarity. This is best done with a voltmeter or multimeter. Start by looking at the supply voltages to the ICs. They will have a couple of pins that are the supply voltage that makes them work. Put your probes across those two pins. If you haven’t got the correct voltage that you expect there, you have a problem.

If you find that the voltage isn’t getting there, you can check to see why. However, if you find that you have somehow got the negative and positive the wrong way around you have probably killed the IC. We’ve all done it and I still do after forty years of being an electronics hobbyist. I destroyed an expensive £20 digital to analogue converter IC by doing exactly that.

Start again from scratch

If you feel you’ve tried everything and you’re getting nowhere then depending on the size of your project you might be better off starting again from scratch. Take everything off the board and start again.

Tip – Simplify your breadboard layouts

Although the pre-made leads are quick to use making your own will simplify your layouts.

Find out how I’ve made a wire-bending form. For this and other tips about breadboards click here.

Build it stage by stage

If you have a bit of electronics knowledge you might be able to build the circuit up in stages and check each stage works before adding other parts.

I built a voltage controlled oscillator using exactly this method.

I had a rough understanding of the circuit so I built it just to get the basic core oscillating. A lot of the circuitry was various other wave shaping and stuff that I added step by step. In the end, it was quite a complex circuit for a solderless breadboard and one that I wouldn’t have been too confident of putting it all together without a mistake and then having to try and track down what was wrong.

By building it in stages I could add a few components at a time and check those parts were working correctly before I moved on to the next stage. Then when I added another new part, in this instance there was a part of the circuit that took the triangle wave and turned it into a sine wave.

I knew the triangle bit was working so when I added the next bit if there was a problem I knew it was something I’d just done.

The circuit diagram is wrong

If you’re certain you haven’t done anything incorrect it could be that the circuit you’re building is the problem and it will never work because it’s wrong.

If this is the case everything is still not lost. Whatever your building can be broken down into stages, oscillators, amplifiers and you can bet the circuitry isn’t unique. You can usually find similar circuits on the internet or in books, remember those.

If you’ve built a circuit using a 555 that isn’t functioning look at the other circuits. If they all have a pin connected to 0v and your design connects it to something else, that may be a problem. There are not many things more satisfying in the electronics hobbyist world than to find a mistake in a design and to sort it out yourself. It can make you feel very smug.

A component is faulty

Another thing to consider is that one of your components is faulty. Any component can be faulty and that won’t be helping your circuit but some components are much more likely to have faults than others.

How to test electronic components title page

The easy way to test electronic components

If you build projects, you’ll need to know how to test electronic components.
This is the quickest, easiest and most foolproof method I’ve found. It’s cheap and will save you lots of time and trouble.

The first thing I would suspect when searching for a faulty component would be an IC.

If you have a known working one plug that in place of your suspect one. These are things that you should only try after checking the wiring. Especially check it to the IC’s you don’t want to take a faulty one out that is faulty because you’ve wired it wrong only to put a working one in its place and then destroy that one as well.

One way around this problem is to take the suspect device out and try that in a circuit that works.

For instance, I have built a function generator, which is a piece of test equipment that generates waveforms. It uses a 555 timer in it, so if I have a suspect 555 timer I know I can check the function generator is working, remove the power and plug a suspect 555 timer into the socket. If the function generator doesn’t work then I know it’s the 555 I plugged in.

This is a good tip for the electronics hobbyist. I’ve built lots of projects using various ICs and if you have a suspect IC that, you’ve used before in a project take the lid of the project and plug the suspect device into your working circuit. That will give you a definitive indication if the IC is faulty or not.

If you’ve built a circuit with an op-amp IC in it you’ve also built an op-amp tester. This goes along with a previous tip of always using sockets for ICs. Check out my article for more information about op-amps.

Common breadboard mistakes – Summing up and final thoughts

Building a project on a breadboard and finding that it doesn’t work is a bit of a disappointment but it doesn’t have to be the end of the world. By following through the steps above you will have hopefully found if you’ve made any common breadboard mistakes.

Find what the problem was and put it right. Making mistakes isn’t a problem. Not learning from your mistakes is.

Once you’ve got your breadboard circuit working you might want to transfer it to a PCB to permanently keep it. If this is the case be sure to check out my Transferring a solderless breadboard to a PCB for some help, advice and tips.

Also check out my post, Breadboards – the complete guide which should give you any other breadboard information.

“Hi, I’m Graham Moore and I’ve been building electronic projects since I was 12. I had a fascination for old radios and taking them to pieces but when my Nan bought me an electric soldering iron, I realised with a few components I could build stuff.

Learning to solder opened up many doors for me as electronics also became a career. I hope you get as much from it as i did”.