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Aric
Aric, Engineer
Category: Home Theater-Stereo
Satisfied Customers: 42006
Experience:  15+ years in the field. Owner of AV Installation, OEM and Repair company
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My Kenwood Stereo Integrated Amplifier KA-76 died while I

Customer Question

My Kenwood Stereo Integrated Amplifier KA-76 died while I was enjoying an Al Jarreau c.d.
The amplifier had been acting tentative for a few weeks...stopping...no sound...back on.
Now it just stopped working for good.
Please help.
A Music Lover
Submitted: 1 year ago.
Category: Home Theater-Stereo
Customer: replied 1 year ago.
Posted by JustAnswer at customer's request) Hello. I would like to request the following Expert Service(s) from you: Live Phone Call. Let me know if you need more information, or send me the service offer(s) so we can proceed.
Expert:  Aric replied 1 year ago.

Hello and sorry you're having problems. There is not a pushbutton fix for this problem, as an amplifier stopping producing sound is a hardware related problem- either there's a component experiencing thermal runaway )it gets hot, causing other parts next to it to get hot, which then increases it's own temperature even more, and so on), or since this is an older unit- the power supply filter caps have drifted out of spec enough to prevent the unit from functioning at all, or in the worst case scenario, the power supply transformer has failed. In order to know what's caused this, you would need to be able to measure live voltages first at the secondary of the transformer in AC, and then after the bridge rectifier in DC and then follow these voltages to see where they're missing. That being said, most people are not up for this type of repair- as unless you're experienced with it, repairing a receiver is not a good first project. Please let me know what you've tried, what experience you have and exactly what the receiver is doing right now and we can proceed.

Alternatively, if you're looking to have this repaired at a shop, you're looking at an average $150-$200 repair cost on this model, which is a heavy chunk towards the purchase of a new and more powerful amplifier/receiver.

Expert:  Aric replied 1 year ago.

Additionally, if you have tools (meter, oscilloscope, and soldering station), then the Service Manual would be of help to you in order to find out what voltages should be present at what points:

http://elektrotanya.com/kenwood_ka-76.pdf/download.html

With certainty, I can say though that the most common failure points on these units, are the power supply filter capacitors (over 10 years old they begin to drift out of spec and require replacement) or the output transistors which drive the speakers directly.

If you can solder, a good place to start would be to replace the 2 large "cans" next to the power supply transformer- by matching up the ratings in "uf" and "DC volts" and then replacing them with units from:

http://www.mouser.com

Or:

http://www.digikey.com

If you need further assistance let me know. Please do not forget to click a POSITIVE RATING before you go- as it's how I am credited for my work. You can follow up at any time, at no additional cost.

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