Wiki contribuído por estudante
Um aluno de nosso programa de educação fez este wiki. Não foi feito pelo pessoal do iFixit.
First Act MA2039 Troubleshooting
This troubleshooting page was created to help people diagnose problems with their First Act MA2039 guitar amplifier.
Amplifier gets too hot and shuts down.
One factor to overheating amplifiers is dust build-up. Dust blocks ventilation often causing the amplifier to reach dangerous temperatures. The best way to remove dust and small particles is to spray the inside of the amplifier with a bottle of compressed air. Remove the back panel of the amplifier so that you can see the open wires, audio board, and other electronic parts. Spray the compressed air onto these parts. DO NOT try to blow away the dust or use a shop vacuum. Your breath can shoot water particles into the audio system that can damage the audio board. The shop vacuum will blow larger bits of debris back into the system. Further explanation can be found here.
Loss of Battery Life in Cartridge
Batteries lose power faster than normal.
Check the battery cartridge for corrosion; It's natural for batteries to eventually leak acid and when left in a cartridge over a long period of time. To clean the cartridge you'll need Q-tips and some vinegar. Be sure to wear protective eye-wear and gloves before continuing. Carefully remove the damaged batteries and place them into a plastic bag. Next, take a Q-tip and dab some vinegar onto the tip. Swab any stained pieces of the cartridge with the Q-tip until clean. More information can be found here.
Battery Losing Charge
A common mistake most musicians make is that they leave their guitars plugged into the jack causing the battery to drain. A majority of amplifiers will use the power within the batteries, whether or not the amplifier itself is turned on or plugged into the wall. Make sure to unplug your guitar cable from the amplifier after every session.
Speaker Inaudible/Not Emitting Sound
There is little to no sound coming from the amp speaker.
Amp is Muted
To ensure volume isn’t turned all the way down or muted you must check the volume knob on the front of the guitar amplifier. On the volume knob there will be some type of painted or indented stripe that will indicate the level of volume. Turn the knob until the stripe is in the 11 o’clock position and test for sound.
A blown speaker can occur if the amp is being played at a high volume for a long period of time. To check if the speaker is blown you will need to remove the back panel of the amplifier. Once the panel is removed and the speaker exposed you will be able to ensure all wires are connected to the speaker correctly. If all wires are connected correctly and there is still no sound, then use a tool called a “multitester”. This tool measures voltages, current and resistance. Connect it to the positive and negative (+/-) connection points on the speaker and set the multi-tester to test for ohms. If the meter reads zero, then the speaker is blown and will need to be replaced.
Dials and Buttons Unresponsive
Crackling, popping, or complete loss of sound when adjusting knobs.
Dirty Knob Connection
If you are adjusting the knobs and you hear crackling, popping, or a total loss of sound, then you may have rusted or dirtied connections. First, try turning the knobs vigorously back and forth in an attempt to dislodge any debris. If that is unsuccessful, then you will need to remove the knobs and thoroughly clean the knob connection points.
Worn/Damaged Adjustment Knobs
Loose or completely unresponsive volume, tone, and gain knobs may be worn on the inside. The plastic knob will need to be removed from the front of the amp to check this. Once removed, look at the notches on the inside of the adjustment knob and notice how these align with the pin the knob was pulled from. These notches align with tabs on the pin which enable it to adjust its specified setting. If they are worn or damaged, then plastic knobs will need to be replaced.
Amplifier Not Turning On
Your amplifier won't turn on.
No Power from Amplifier
First check to see if the power is plugged into the outlet and into the amplifier. Try unplugging the connection to the amplifier, cleaning the connection, and re-plugging the connection to the amplifier. Proceed by plugging the power adapter into the outlet. If problems persist, get a new power adapter.
Damaged Wire Connection
Getting your amplifier to turn on will be one of your troubleshooting battles you don’t want to deal with. If you originally had a problem with the "Amplifier Overheating" section, this may be a prior symptom of the current problem. Check to see if the batteries in the amplifier are providing power to the unit. If the batteries are not the concern, you may want to check for damaged wires. You can use a multitester to measure resistance through the circuit terminals of the wiring to make sure the internal components are functional. Refer to "Blown Speaker" for details on the multitester.