- If you need clarification, ask it in the comment box above.
- Better answers use proper spelling and grammar.
- Provide details, support with references or personal experience.
Tell us some more! Your answer needs to include more details to help people.You can't post answers that contain an email address.Please enter a valid email address.The email address entered is already associated to an account.Login to postPlease use English characters only.
Tip: The max point reward for answering a question is 15.
Depends on what sound it is. If it's a hum, then it could be a fault. If the hum is on one channel then the place to look is that channel. You can compare the good channel with the bad one for clues as to what.
If it is in both channels then you are looking at the power supply. Or something common to both channels.
Hum is most often caused by Electrolytic Capacitors.
Crackling noises are caused by resistors, or transistors, or IC's.
Hum or buzz is often caused by the mains filter capacitor letting the 50hz mains hum into the system. Regardless of voltages you just need to try new capacitors. If that doesn't cure it, the problem is elsewhere. If it's a stereo amp and the buzz is on both channels then it's something common to both channels.
Your best way to deal with this issue is to do some "hum tests" inside the unit with it on. Since only one channel is faulty and they are identical, you can use the good channel as comparrison with the bad. You simply touch with you a plastic tool or if you can your finger - not touching metal parts though - and either channel will buzz. Chances are you will come upon the faulty part and make it crackle.
As voltages drop, electronics gets unstable as it goes down and becomes noisy... this may be the nature of this beast. Opening the standby might be the best way to avoid the problem.. Here is your schematic for service:
Switch on your amp, keep its volue down to extreme low, and listen if there is still hum through the left channel or not. If still there is hum, the left side power amplifier section inside the amp;ifier is faulty. If htere is no hum at this state, hum enters thorugh the audio input terminal, and the input wires must be checked for open sheild connection. OK.
The surface mount ic= MC33079D , 14 pin quad low noise op amp is likely at fault, IF the amp is NOT showing a fault light. A LM324D surface mount will also work in a pinch. It's located on the input pcb attached to the input jacks.
There are a few variants for this model depending upon the serial number. From your description, there are some capacitors in between the amp stages called coupling caps that are failing. The hum is some DC current being passed through the output stage. The crackling is probably just dirty controls.
I am afraid not. That crackling is a component in one of the solid state amp circuits starting to fail. These are all soldered into the printed circuit board. This could be a difficult repair to find an intermittant component. Depending on how old the unit is and how much it cost will factor in on if you have it repaired or not. Rule of thumb is that if the unit is two to three years old and cost less the 200 to 300 bucks you should not invest more then 100 to 150 bucks into it. Good Luck