Kenwood Eleven III Repair And Restoration
This Kenwood Eleven III receiver is in rough cosmetic condition. It was in a Florida attic for many years and needs some repairs and restoration.
The wood case is also in pretty rough shape. This Kenwood Eleven III was put out to pasture many years ago.
With any vintage stereo repair or restoration there is always a lot of cleaning to do. This vintage Kenwood receiver from the late 1970's is no exception.
Warm water, dish soap, toothbrush, and rags go a long way to getting the year's of dirt off.
Q-tips also easily and safely removed grime from the tight areas.
I removed the chassis from the wood case. It's pretty dirty in here also.
The picture below shows a close up of the dirt that built up over the years inside this Kenwood Eleven III solid state receiver.
Another picture showing the level of grime on the chassis. This clean up job is one to be done outdoors.
Some compressed air along with a brush will go a long way to getting the dirt and grime off the chassis.
After some cleaning the chassis on this Kenwood Eleven III receiver is looking better.
I have removed the control knobs as well as the faceplate to continue the cleaning process.
Always start with warm water and dish soap before trying something stronger. You will use plenty of rags and Q-tips.
The inside of the faceplate is shown below. There so much dust and dirt that it looks like shag carpet. It should look like the cleaned aluminum.
After some cleaning I'll use a variac to power up this receiver for the first time. Any vintage audio restoration involves a lot of cleaning.
It's not a surprise that most of the 40 year old lamps are burnt out in this Kenwood Eleven III.
I'll replace these burned out 8 volt lamps with Led's.
You can purchase LED kits on the internet but I decided to make my own for this Kenwood Eleven III restoration.
It's takes a while to make these but you will learn a new skill for your next vintage stereo restoration.
This receiver uses 9 different indicator lights to indicate if you have selected FM, AUX, PHONO etc. So 9 Led assemblies need to be built.
Every vintage audio restoration includes cleaning the control switches and pots with deoxit.
Don't forget to clean the back panel RCA jacks and speaker connectors with deoxit.
This Kenwood Eleven III took a hit at some point and one of the AC plugs is broken.
The Kenwood Eleven III solid state receiver is unusual in that it has a built in timer.
If your Kenwood Eleven III will not power up this is the first place to look. This one was broken at the shaft. I bypassed the timer.
This receiver had intermittent audio. Tapping the speaker relay on the power amp assembly would bring the sound back temporarily.
Fortunately this relay is still available from www.mouser.com part #653-MY4-02DC24.
You will need to remove 4 pins from the new relay. The old relay is shown on the left and the new relay on the right.
You will need to remove the power amplifier assembly from the chassis to unsolder the relay. Always have the service manual available for reference.
Now that you can get to the relay you will be able to unsolder it and install the new one. Replacing this relay can fix many intermittent audio issues.
With the new speaker relay installed this Kenwood Eleven III receiver is one step further to making some music
Another intermittent issue is being caused when I tap on the speaker selector board. This causes the right channel to come and go.
First I removed the connectors from the speaker selector board and cleaned the pins. This made no difference as I still had the same issue.
I then resoldered the connector pins. Bingo! That fixed the intermittent right channel issue. Reflowing of solder is sometimes what's needed.
This Kenwood Eleven III receiver is about ready for some bench testing. Any vintage audio restoration should include bench testing.
My ears say the receiver sounds pretty good and it looks better but we will see if the bench equipment agrees.
I'll check and adjust the output transistors bias. Always use the service manual for whatever piece of vintage audio equipment that your working on.
A signal generator helps both for measurements and for the repair of vintage stereo equipment.
The Sound Technology 3200A is vintage itself but it does a good job of accurately measuring amplifier power and distortion.
This Kenwood Eleven III solid state receiver performed well on the test bench and the wood case received some needed wax.
This Kenwood Eleven III is ready to start it's next 40 years. It's time for some music! This repair and restoration is complete.