This Fix-It guide on amplifier service describes how audio amplifiers work, common problems, how to identify amplifier problems, and the parts and tools that need repair. It then gives simple step-by-step instructions on how to remove the amplifier, and tells you how to inspect the amplifier and how to clean the amplifier. Please also refer to other repair guides for other repairs of the amplifier.

How does the amplifier work?

An amplifier is an electronic device used to amplify and control the audio source of a built-in AM-FM receiver and an external CD player, tape player or other home entertainment equipment. The output signal is fed to the audio speaker.

What happened to the amplifier?

Amplifiers can produce errors, the most common being operator errors. That is, if all lights are on but there is no sound, the speaker wire may not be connected or the speaker button may not be selected. Otherwise, the power cord may be damaged or the internal fuse may blow.

One of the most common causes of receiver problems is oxidation of electrical contacts and sockets. A jack is a connector used to mate a wire or plug with a circuit. Noisy jacks or plugs do not conduct electricity, so the next connected device will not receive a signal.

Usually, the problem is not the amplifier, but one of the connections between the amplifier and the signal source or speakers. Please use a continuity tester or meter to check the continuity of the audio cables in and out of the amplifier before attempting to open the device and take a closer look.

How to determine amplifier problems?

It is easy to find the problem in the amplifier: no power, no sound or bad sound. It is more difficult to find the source of the problem. In some cases, the problem actually lies in the audio unit that feeds the amplifier, such as a CD player, cassette tape, DVD player or speaker.

Take our amplifier as an example, our amplifier machine has temperature protection, overvoltage protection, and overcurrent protection. If the protection indicator lights up for a long time, it means that a component in the amplifier is burned out and needs to be replaced, or some cables or components may be loose.

Make sure to unplug the power cord from the wall outlet.

Loosen the screws on the side, back or bottom to separate the cover from the chassis.

Slide the two halves apart to expose the internal components installed on the chassis (lower frame).

Check whether the inner end of the power cord is loose or damaged due to pulling (common problem), and replace it as necessary.

If there is no power, but the power cord is normal, look for the internal fuse. Test the fuse and replace as necessary.

Use a can of compressed air to carefully blow away the dust attracted by the electronic components. If there is too much, use a vacuum cleaner with a plastic tip to clean the inside of the device (so that the fragile parts will not generate static electricity).

Clean the input jack and speaker terminals with an electrical contact cleaner. If one of the input jacks is disconnected from the wire, please reconnect or re-solder.

Use a universal meter to test all fuses.

Use a universal meter to test all fuses.

If these measures do not solve the problem, please seek professional help. Modern audio equipment is made of precision components that cannot be repaired. Instead, they were replaced. The audio professional engineer will know what to replace, where to obtain it and how to complete the work.