What would you do without your music? Hopefully, you won't find out because fixing an amplifier is a little more complicated than most things in your home. Fortunately, there are many things you can do to make your amplifier work without taking it to a repair person.
How Does It Work?
An amplifier is an electronic device that magnifies and controls audio signal sources from a built-in AM-FM receiver as well as an external CD player, tape player, or other audio home-entertainment device. The output signal is fed to audio speakers.
What Can Go Wrong?
Many things can go wrong with amplifiers, the most common being operator error. That is, if everything lights up but there is no sound, the speaker wires may not be connected or the speaker button may not be selected. Otherwise, the cord may be damaged or an internal fuse may be blown.
One of the most common causes of receiver problems is oxidation of electrical contacts and jacks. A jack is the connector used to mate a wire or plug to a circuit. A jack or plug that has gunk on it won't conduct electricity, so the next device in line doesn't get the signal.
Often, the problem is not in the amplifier but in one of the connections between it and either a source or the speakers. Use a continuity tester or a multimeter to check continuity of audio cords going in and out of the amplifier before attempting to open the unit up and look further.
How Can I Identify the Problem?
Identifying the problem in an amplifier is easy: no power, no sound, or bad sound. Finding the source of the problem is a little more difficult. In some cases, the problem will actually be in an audio unit that feeds in to the amplifier such as a CD player, cassette deck, DVD player, or speaker .
Fix-It Tip
One of the first things you can try is to remove all other audio sources from the amplifier and use only the internal receiver to determine whether the unit is getting power or good sound.
What Parts, Materials, and Tools Do I Need?
Once the chassis is open, look for obvious damage such as loose or burned wires.
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- Phillips screwdrivers
- Soldering iron and solder
- Electrical contact cleaner spray or can of compressed air
What Are the Steps to Fixing It?
Amplifiers are made up of many of the same components as other appliances, so fixing basic things is similar. For example, cords may not consistently deliver electricity, switches and controllers can cause problems, and fuses may need to be replaced. Frequently, what the amplifier needs most is a good cleaning.
Use a multimeter to test all fuses.
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Disassemble an amplifier:
- Make sure that the electrical cord is unplugged from the wall receptacle.
- Remove screws on the side, back, or bottom to separate the cover from the chassis.
- Slide the two halves apart to expose the internal components mounted on the chassis (lower frame).
- Inspect the internal end of the electrical cord for looseness or damage caused by being pulled (a common problem) and replace as needed .
- If there is no power, but the cord works, look for an internal fuse. Test the fuse and replace as needed.
- Use a can of compressed air to carefully blow away dust that is attracted to electronic components. If excessive, use a vacuum cleaner with a plastic tip (so delicate parts won't receive static electricity) to clean the inside of the unit.
- Use electrical contact cleaner to clean the input jacks and speaker terminals. If one of the input jacks is disconnected from the wires, either reconnect or resolder it.
Besides fuses accessed from the back of the cabinet, many amplifiers include one or more internal fuses.
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Fix-It Tip
Use a clean pencil eraser to clean cable pins on a regular basis. Use a quick shot of compressed air to remove eraser debris.