Pub Sub
New Member
Hey all! Yesterday I bought a Kenwood KA-8100 that was advertised as broken. Today I need help in restoring it.
The inside and outside of the unit are pretty darn clean. It appears as if one corner of the unit took a drop head on and bent but did a pretty good job of protecting the internals.
After brief testing, the relay would not close so no audio at all was getting through. When powered on, the LED worked and the headphone output gave my headphones some noise from fiddling with controls but nothing from the volume control.
Today, I opened the case. After a decent inspection of components on the amp board, I see no obvious hot or damaged components. One leg of two output transistors shook loose from their solder, so I resoldered them. This changed nothing.
After some fiddling around, I accidentally shorted two connections in the relay circuit for a split second on the underside of the board. At this point, after a restart of the unit, the relay clicked closed at power on and clicked off shortly after power down. The issue now is that I am seeing 52v being output from the amplifier section. I plugged in headphones which resulted in some loud electrical noise coming from the headphones and some smoke coming from the jack.
I would be forever greatful if someone is willing to help me troubleshoot this unit. I would love to get it singing, and don't have the money at the moment to pay a professional to go through it. I do have a small budget for repair components and such. I have a digital multimeter and hand tools, but little knowledge of electrical components. The service manual for this unit seems very detailed, but I am mostly inept at reading electrical schematics.
I found the service manual here:
https://www.hifiengine.com/manual_library/kenwood/ka-8100.shtml
Thanks all for any help you can offer.
The inside and outside of the unit are pretty darn clean. It appears as if one corner of the unit took a drop head on and bent but did a pretty good job of protecting the internals.
After brief testing, the relay would not close so no audio at all was getting through. When powered on, the LED worked and the headphone output gave my headphones some noise from fiddling with controls but nothing from the volume control.
Today, I opened the case. After a decent inspection of components on the amp board, I see no obvious hot or damaged components. One leg of two output transistors shook loose from their solder, so I resoldered them. This changed nothing.
After some fiddling around, I accidentally shorted two connections in the relay circuit for a split second on the underside of the board. At this point, after a restart of the unit, the relay clicked closed at power on and clicked off shortly after power down. The issue now is that I am seeing 52v being output from the amplifier section. I plugged in headphones which resulted in some loud electrical noise coming from the headphones and some smoke coming from the jack.
I would be forever greatful if someone is willing to help me troubleshoot this unit. I would love to get it singing, and don't have the money at the moment to pay a professional to go through it. I do have a small budget for repair components and such. I have a digital multimeter and hand tools, but little knowledge of electrical components. The service manual for this unit seems very detailed, but I am mostly inept at reading electrical schematics.
I found the service manual here:
https://www.hifiengine.com/manual_library/kenwood/ka-8100.shtml
Thanks all for any help you can offer.
