Guitar Amp Not Working but a Light Is On? How To Fix It


guitar amp not working but a light is on

As a guitar player, one of the most frustrating problems you might encounter in life is your amp acting up and refusing to work. It is even more frustrating if the problems seem contradictory, like the amp turning on but producing no sound. Such problems need careful deliberation, and you must tread carefully if you wish to correctly diagnose and solve the problem. 

If the light is on, but the amp is not working, it implies that there is a problem with the wiring or the preamp or amp. Another thing it might point to is a blown speaker. You should also rule out any trivial problems that may arise before you proceed. 

This article will cover why your amp might refuse to make sound despite being on. We’ll go over what you can do to correctly diagnose and fix this issue, so you can soon go back to your riffing and soloing. 

guitar amp not working but a light is on

Rule Out Trivialities

Many seemingly complex guitar problems are often caused by trivial things that we simply don’t notice. Instead of rooting out the simple issues first, we’re often prone to beating our heads against the wall in frustration because we can’t find the source of what’s preventing us from playing music. All the while, the basic issues are right under our noses. 

I’ve been frustrated with my amp not working countless times, only to see that my guitar’s volume was turned all the way down. When facing a problem, it’s best to go over the most basic problems to save yourself time and potentially money. 

Often, a guitar amp not working will seem catastrophic, and we’ll automatically look for a big problem, ignoring everything else. You might think at such moments that so much trouble can’t be caused by something simple. 

However, checking for trivial problems and solving them on the go will only take a few minutes, and it might prevent you from wasting time and money on a wild goose chase. Plus, you risk causing damage anytime you change something on your amp, which might set you back a few hundred or even a few thousand dollars. 

Instead of risking that, go through the basics first. Here are some things you should do:

  1. Check if the cable is working.
  2. Inspect the jacks for rust.
  3. See if your guitar is turned up.
  4. Check if the amp is turned up.
  5. Inspect the pedals.

Let’s briefly examine why these things are important.

1. Check if the Cable Is Working

A faulty guitar cable won’t allow signals to be transferred from your guitar to your amp, making it sit quiet. Guitar cables break and get damaged easily, plus they are prone to corrosion and oxidation, so it is very likely that you’ll have problems with your cable rather than amp. 

If you have a spare cable, try using that one to connect your guitar to the amp. It only takes a minute of your time and might save you from a big headache down the road. 

It is always a good idea to have more than one cable precisely because of this kind of situation. It’s even more important if you play live. You don’t want to be left without a cable during a concert, so you have to walk off the stage in shame. 

You can also inspect the cable for signs of corrosion and physical damage. These are sure signs that the cable is not fit for use anymore, and you shouldn’t feel sorry to throw it away or keep it as a weird decoration.

check if the cable is working

2. Inspect the Jacks for Rust

Jacks tend to corrode if your musical equipment is not stored properly. It doesn’t happen that often, but it is an occasional occurrence, and it is very easy not to notice this problem until it is too late. 

This can happen to the output jack on your guitar and to the input jack on your amp. If you are really unlucky, it might happen to both. This will naturally prevent your guitar’s signal from being transmitted, resulting in a silent amp. 

Jacks are easily replaceable, so even if something is wrong with them, you can get rid of the problem quickly. Replacement jacks usually only cost a handful of dollars, and as long as you buy the right ones, there will be no problems. 

3. See if Your Guitar Is Turned Up

This should go without saying, but it happens more often than one might think. It’s very easy to forget that your guitar’s volume knob is turned all the way down, and you might start strumming without turning it up. 

Usually, people figure it out after a few moments, but it’s not completely impossible to see someone desperately looking for a solution for their silent guitar amp only to figure out that their guitar was simply turned down. 

While this usually results in a good laugh, it is best not to waste time on such a trivial problem, so make sure that your guitar is turned up. It’s good to develop a habit of checking for this before you begin playing, so you’re sure that everything is set up correctly. 

4. Check if the Amp Is Turned Up

This is almost identical to the first problem. You might easily turn on the amp while forgetting about the master volume knob and leaving it turned down. This will give you the wrong impression that there’s something wrong with the amp, while it’s functioning perfectly and the problem is you. 

It is best to always take a few minutes to inspect the knobs on your amp and set them up according to your needs. This will let you notice if the master volume is turned down, preventing frustration. 

check if the amp is turned up or inspect the volume knobs

5. Inspect the Pedals

Pedals can often cause problems with your gear. The more pedals you have, the more things can go wrong. If you are the kind of guitarist who likes to play around with pedals, take a close look at them if you run into problems.

Make sure that all the cables are connected properly and that everything is turned up. With a bunch of pedals, it is very easy to overlook a misconnected cable or one that is not connected at all. 

Once you’ve gone through all the trivialities and the problems are still there, you can move on to more serious troubleshooting steps. Let’s see how. 

Why Is the Light On, but There’s No Sound?

If the light on the amp is on, but the amp is not making any sound, it means that it is powered properly, so there is probably no need to inspect that. However, the speaker, preamp, or amp might be the problem. This requires close inspection, but it’s not too difficult to get to the root of the problem.

Let’s see what you have to do. 

Listen

The key to troubleshooting problems with your amp is listening to it carefully. If there is absolutely no sound coming from the amp’s speaker, not even floor noise, the speaker is likely blown. This occasionally happens to guitarists who play at exceedingly high volumes. 

On the other hand, if there is some hissing or buzzing, the speaker is likely working properly, and the problem is in the preamp or internal circuitry. This problem is somewhat worse, as it requires more technical knowledge, and those parts of the device are more intricate in their design. 

How To Deal With a Blown Speaker

If your amp speaker is blown, you can either replace it or fix it. Replacing is more common, but it’s not as daunting as it seems. Fixing it is also not a particularly difficult task, and anyone with a basic grasp of soldering and electronics can pull it off. 

Here’s what you have to do:

  1. Unscrew the grill covering the speaker.
  2. Gently remove the speaker
  3. Inspect the cone and the voice coil, looking for tears and ruptures.

If the speaker cone has a small tear or rupture, it can be easily fixed with scotch tape or glue. If it is completely destroyed, you’ll have no choice but to replace the entire speaker. Fixing such a cone would probably not yield great results. 

technician fixing the speaker

On the other hand, a voice coil can’t be fixed or replaced. If the voice coil is damaged, there is no choice but to replace the speaker. Replacing is a bit more difficult than fixing, but if you’re not confident in your skills, find a technician to do this for you. 

If you are certain that you know what you’re doing, you can try changing the speaker on your own.

Here’s what you have to do:

  1. Record the speaker’s serial number, resistance, and power handling information. You need this information to find the right speaker.
  2. Scour the Internet and physical shops for a replacement speaker. Don’t skimp out on it. 
  3. Remove the old speaker.
  4. Solder the wires to the new speaker.
  5. Put it in the hole.
  6. Test the new speaker.
  7. If it works, reattach the grill. 

Speakers are not replaced that often. Guitarists more often replace their amps, but it is much cheaper to replace the speaker, and it’s far less wasteful. Throwing away the whole amp is not the best idea if the other components still work properly. 

Plus, installing a new speaker might do wonders for your tone. You’ll easily find a speaker that is much better than your old one, which will have an overwhelmingly positive effect on your sound. Thus, you can turn the misfortune of having amp problems into a benefit. 

What To Do if the Speaker Works Fine

If there is some noise coming from your speaker, it means that it would also transmit the signal from your amp if there were any. This points to a problem with the amp circuitry. The bad news is, this problem can be anywhere in the circuitry. 

However, with some knowledge of amp circuitry and careful listening, you can easily narrow down the problem to small parts of the circuitry and fix the problem that way. Let’s see what to look out for. 

You should primarily listen to the noise floor. Noise floor is the noise your amp makes on its own, even if there is no signal. If the noise floor is quieter than usual or not present at all, you likely have a problem with the amp. 

The presence of noise floor implies that the amp is working more or less correctly, but the signal from your guitar just can’t reach it for some reason. If there is noise floor, but it’s quieter than usual, it might imply a problem with the preamp.

Noise floor can also be louder and more aggressive than usual. This implies that there is a broken piece that introduces the noise. That can be an active component such as a transistor or tube, or a passive component. They’d have to be replaced in both cases to solve the problem.

However, listening for noise floor is not completely reliable. Most people won’t even know what their amp’s noise floor is like generally, which makes it difficult to see if there is a difference from the noise the amp usually makes.

It’s also possible that the amp was broken the entire time you’ve had it, so you don’t have a clear idea of what its noise floor sounds like. On the other hand, if it has worked well, then the noise floor was probably quiet and unobtrusive, so you may not have even noticed it. 

However, listening for noise floor will give you a rough idea of what might be wrong with your amp, which is always a great beginning. You’ll have to inspect the amp physically as well, but at least you’ll know what to look at. 

Check All Inputs and Outputs

If your guitar amp has more than one input, you should test both. If neither produces sound, then the problem is likely in the circuitry after the channels merge. If one is silent, then the problem is likely only in it, which greatly narrows the problem.

If there is an aux output, test that one as well. If it makes sound, there is probably a problem within the circuitry after the aux. If not, then the interruption most likely precedes it. 

After locating the problem, inspect the area closely to see what might be happening. When it comes to replaceable parts like tubes, you’ll simply have to install new ones. If there is a problem with the wires, you’ll likely have to resolder them. 

You should also get rid of any debris that you find. Dust and other particles can interfere with the signals and diminish the sound quality you get from your amp. Even if that’s not the root of the problem, you should always take a minute to remove dust and other kinds of dirt. 

Taking Care of Your Guitar Amp

The best way to deal with amp problems is to avoid them in the first place. Investing a bit of effort in the maintenance of your guitar amp will save you a lot of trouble and will mean that you won’t have to spend your time chasing problems in your amp’s circuitry instead of jamming. 

taking care of your guitar amp

You should always keep your amp away from extreme temperatures. Both extreme heat and extreme cold might damage it and ruin its sound. While you won’t have problems after driving in a cold car with your amp to a gig, consistently keeping your amp in a too cold (or too hot) room won’t be good for it. 

It should also be protected from dust at all times. The easiest way to do this is to buy an amp bag, but if that’s not an option, covering it with a blanket or a piece of nylon will do the job just fine. Dust is one of the biggest causes of amp problems, so eliminating dust will eliminate most of the problems. 

Another huge cause of problems is liquids. As you can imagine, getting your amp soaked in coffee or beer will not positively impact its tone. Even though it might be tempting to put a coffee mug on your amp while playing, the convenience of it won’t make up for the potential damage if you spill the coffee. An amp is not a coffee table. 

Of course, your amp should also be protected from impact and pressure. Don’t let it tumble around your car’s trunk and don’t put heavy objects on it. Be careful not to hit it when carrying it, and don’t ever drop it unless you want an amp in pieces. Most of all, don’t sit on it, even if your legs hurt like hell. 

Conclusion

If the light on your amp is on, but the amp is not working, that means that your amp is powered, but some internal components are broken. It might be the speaker, which is easier to fix, but it might be the amp circuitry, which is more difficult to diagnose and fix. You need to carefully inspect your amp and listen carefully for the noises it makes, which will help you determine where the problem is.

David Sandy

Hey there! My name is David Sandy and I'm the founder of Sandy Music Lab. I've been playing guitar for several years now and created this site to be able to share and explore music with others. Check out my recommended guitar gear!

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