QuestionQUESTION: Hi, I am having trouble with my Aiwa AV-D58 receiver. Display looks fine and seems like its changing the sources fine, but there is no sound at all. I made sure "Tape Monitor" is not selected.
Opened the box and nothing looks fried inside. Tried eveything known in the manual but nothing seems to help. Any help or suggestion will be appreciated.
ANSWER: This is a DTS, Dolby 5.1 surround sound receiver. Good unit and should be working okey, of course.
Here is what I recommend:
- Unplug the power cord for 30 minutes.
- While unplugged, disconnect all speaker wires at the rear of the receiver.
- Then power it up again and check all the settings. Play the tuner or cd or any audio to see if it seems to be working okey.
- Connect only one speaker, being careful not to touch the wires or short anything. If in doubt, turn the set off while connecting the speaker, then power it up again.
- Go around with the good speaker and one by one check for sound coming from each amp.
IF: You get no sound from any of the amp outputs there is probably a main power supply failure that feeds the audio amplifiers. In this case you will need a service tech to diagnose with instruments what the problem is.
If one or more of the amps is working and the others are not you will need to have the output transistors replaced in the bad channels. They fail most often from overdrive or playing too loud OR from shorts on the speaker lines.
Hope this will help.
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QUESTION: Tried all these attempts but to no avail.
While I was looking closely to the circuit board, I noticed that the back side of the circuitboard exactly behind IC601 looks discolored(brownish) from heat from that IC or transistor. Was just wondering if you are aware if thats a common known culprit.
Anyother suggestions to check or troubleshoot further.
Thanks for all your help/suggestions so far.
AnswerThanks for the feedback.
No, that is not a common ailment for a receiver. But it is not unusual, either.
The cause can be anything relating to that IC. Something that causes excessive heat is generally a shorted condition that allows excessive current to heat up the IC. Of course, it could be one of the components very near the IC and not the Ic at all. Can you see on the other side of the board where the discoloration is; search for a burned or discolored resistor or some component.
My suspicion is the solution will require an expert tech to take some measurements to track down the guilty parts. There are too many possibilities for long-distance analysis.
