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How To Fix A Car Amp – A Comprehensive Guide

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Have you turned on your car audio system before and no sound comes out? The volume has also been increased, yet it stays the same. This is a simple indicator that your amp has an issue. 

Your amp may be blown but we can show you how to fix a car amp. Do not worry, we will make this simple. You do not have to be an expert in electronics to be able to fix a car amplifier. But you will need a little training to do it perfectly.

How to fix an amp
Photo credit: Malte Luk, Pexels.com

A car amplifier comes with channels that could be mono, 2, 4, 5 or 6. The number of channels required depends on the setup of the speaker. Most Amps like the Planet Audio AC1500.1M have very good speakers.

At some points, your car amplifier may malfunction. Some of the common problems your car amplifier may have include: 

  1. Distortion of sound
  2. The amp will not give out any sound
  3. It will give off strange sounds that sound like hissing, whining, or farting
  4. Protect mode indicator may give off light
  5. The car audio may not power at all
  6. It may even become very hot

However, the cause of these problems can be traced. So, what are the tools you need in troubleshooting car amplifier problems?

Tools Needed for Car Amplifier Repair

  1. A set of screwdrivers
  2. Soldering iron
  3. Desoldering pump
  4. Solder
  5. Soldering flux
  6. Wire stripper
  7. Crimping tool
  8. Scissors
  9. Portable blower
  10. Nose pliers
  11. Combination pliers
  12. Allen key Wire cutter
  13. Multimeter or multitester
  14. Emery paper
  15. Knife
  16. Electrical contact cleaner spray

You will need these tools if your car amplifier does not have power. However, if you are a Do It Yourself (DIY) kind of person, you should have a toolbox.

This is just in case you will need any other tool that was not mentioned in the list above and here too. 

Video: How to Fix an Amplifier

This video explains in detail how to fix common issues you may experience while using the amp.

Steps Involved in Fixing A Car Amplifier

Step One

Open the cover of your car amplifier and take pictures of it. This is rare advice, but it will help you to identify and recall the areas that are bad. Ensure that the pictures are of high resolution too. 

Taking a photograph of the car amplifier will enable you to recall how the amp looked before it was dismantled. Also, if in any case, you cannot fix the problem, you can send the pictures to a handyman. 

This implies that the specifications of the car amplifier have to be clear. These include the model, brand, serial number, etc.

Step Two

Check if there are any loose plugs as this is usually the first suspect when it comes to amp problems. Examine the jacks critically, both the inlets and outlets. Also, look at the power supply cable to be sure that it is still ok.

Step Three

Check the speaker wires. These are the wires that run through the back end of the amplifier to the speaker. Use your multitester to check if there is some current running through the speaker wires. Most importantly, ensure that the wires are properly connected.

At this point, you may need to break the supply of power to all sources of audio in the car. But power should be supplied to the internal receiver. At this point, you can turn on the amp to see if it will power on or give off a good sound.

Step Four

If step three does not solve the problem, you will need to try other things. Check the cartridge fuse of the amplifier.

It should either be mono or more. It is usually cylindrical with each end having metal caps that serve as contact points.

If the fuse is blown, the metal filament inside the fuse will be totally burnt. This means that you will have to replace the fuse. But you can still use your multitester to check if there is a current flowing in the fuse.

When changing the fuse, you need to replace it with the exact type as the former one.

Step Five

Your car amplifier may receive signals that there is a problem with the car audio system connection.

This will cause it to switch to protect mode. When this happens, an indicator light will keep blinking to signify that the car amplifier is in protect mode.

More so, the protect mode is a safety function of the car amplifier that prevents the internal components from getting damaged. When you discover that the protect mode is on, stop power supply from reaching the speaker wires.

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After that, if the protect mode turns off, it implies that the speakers are faulty. Examine the speakers to see if the connections are in order.

You can as well change them and check the amp again to see if it will function properly this time.

However, if the power mode is on due to faulty wires, you may need to change the RCA wires.

Ensure you buy superior wires. When this is done and the indicator light turns off, the problem has been fixed.

There are other reasons why your amp can go into protect mode. They include:

  1. If the amp was not properly installed
  2. If the amp was overheating
  3. If some wires have become loose
  4. If the amp is internally damaged

Step Six

If the previous step did not solve the problem, then you need to check if any of the internal components are burnt.

At this point, if your amp is powering on but does not give off the sound, open the amp and check the printed wiring card or board. The printed wiring card is the building block of all electronic devices.

All electrical components of the device are found on the printing wiring card. This card is also known as the printed circuit board (PCB). 

Take a critical look at each component of the card or board.

If there is a transistor, resistor, or capacitor that is burnt, change it and see if the amplifier will be restored.

Step Seven

Check every component of the printed circuit board (PCB) that was soldered.

You can gently tug the wirings to see if any of them will come loose. If there are loose wires, use your soldering iron to solder the connected parts or joints.

After soldering, your soldered joints should look shiny and clean. If this is not the case, it means the joints were not properly soldered.

This can affect the connections of the amplifier.

Step Eight

Use your multitester to check the resistors. Usually, resistors have colors that indicate their resistance. But if you cannot decipher that, you can set your multitester to ohms or resistance. 

Power on the amp and place each probe of the multitester on both sides of the resistor. Reading will be displayed in ohms. The displayed figure indicates the measurement of the resistance.

It usually has a variation of 5 percent. Repeat this for each resistor. However, if nothing displays on the multimeter, it means the resistor is faulty.

Step Nine

At this point, you need to check the output transformer of the amp. This is the component that supplies power to the speaker wires.

Power off the output transformer wires to check if there is any voltage flowing through it.

Ensure that your multitester is set at Volts. Remember that it should be Direct Current Volts because you are trying to check the volts that are coming out of the wires.

If there is no voltage flowing out of the wires, it is an indicator that the transformer is burnt. If this is the case, all you need to do is buy a new output transformer.

However, the voltage may be high in an abnormal way or very different from what you may find in the car manual.

When this happens, it means that the transformer is open or has a leakage point. This also means that the transformer is bad and needs to be replaced.

How to fix a car amp
Photo credit: Anthony, Pexels.com

Precautions to Take When Fixing A Car Amplifier Repair

The following precautions should be taken when attempting to repair a blown car amplifier:

  1. Ensure that the amp is deactivated.
  2. Turn off the engine of the car and remove the key from the ignition.
  3. Always use your nose pliers to pick the fuse.
  4. Always replace a bad fuse with another of same amperage. Using a wrong fuse or one with an amperage that is higher than the initial one may lead to a fire outbreak.
  5. Recheck your car manual before replacing any fuse.
  6. Do not touch any broken wire with your bare hands. Ensure you turn off the power supply before handling it. 

Next Steps

It is important to note that the steps described above are for resolving amp power and sound issues. If at any point you become uncomfortable, you can give it a break.

It may be your first time with electronics but with patience and perseverance, you will get your desired result.

On the other hand, you can call a friend who is good with electronics.

You can have him standby while you try your hands at solving the problem. This may boost your confidence level.

Remember getting a good amp saves you the stress of having to fix your amp regularly and we recommend the Planet Audio AC1500.1M Car amp for its durability.

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