Help! No sound kenwood kr 8010

[roger2]

If you can get something to work it would be a good starting point, lol.

I guess I get confused easily. But aren't we discussing three things at once?
1) ipod to aux or tape in (play)
2) ipod to main-in
3) pre-out to aux or tape in (play)

Item 1 is safest, and is a normal hook-up mode. Items 2 and 3 entail some risk and if you do either you must make sure that all volume controls begin fully off.

For item 2 establish connection with the 8010 turned off, 8010 volume down, and ipod on but volume down. Then turn on power to the 8010 and then very slowly turn up volume on the ipod. Volume on the 8010 should be irrelevant, but leave it turned all the way down anyway.

Item 3, I am not sure I would try, or possibly I would... very carefully, but would not suggest someone else do it. Maybe someone can clarify. Definitely would have two pre-amps in series and, I believe, potential for making smoke.

 

[petehall347]

number 3 fine by me .
pre out is line level .tape in/play is line level .
thats as long as one unit into another . doing this on same unit no problem but wont do much except waste your time .

 

[roger2]

But pre-out is controlled by the volume control. When turned up is it not possible for that to be greater than line level? Pre-amps do have gain, no?

 

[petehall347]

line level is line level . vol control attenuates it when turned down . it wont go higher than it can when turned up .
granted some preamps have higher output than others .this information should be in the manual .

 

[Bonvivant25]

Ok, update. I used method 1 and got music through my good amp. It was strong but it will need some attention later. No. 2 did not work. Still no relay click. So I gather that the problem is on the amp side?

 

[petehall347]

yes the main amp needs looking at for sure .

 

[Bonvivant25]

How do you recommend that I should proceed?

 

[petehall347]

slowly and carefully with some methodical thrown in .
either take it in or if you want to fix it yourself you will need some basic tools and basic skills and follow instructions well .

 

[roger2]

Ok, update. I used method 1 and got music through my good amp. It was strong but it will need some attention later. No. 2 did not work. Still no relay click. So I gather that the problem is on the amp side?

Please clarify your connections for method 1. Was this excluding the 8010 completely, and simply connecting the ipod to the other receiver?

If you haven't confirmed output from the 8010 pre-amp, then IMO things are still being rushed.

Like pete said, slow, careful, methodical... I am not yet completely convinced that switches on the 8010 are in the correct positions. The face plate is removed, making it easier to misinterpret something. And previously (other thread) , you began with the assumption that the main outputs are blown with no diagnosis or testing...

 

[Bonvivant25]

I have the tools. I want to fix it myself. I really want to gain an understanding of these types of electronics. I know how to solder. I am handy. I am thinking that I should start with the power supply and protection circuit.

 

[Bonvivant25]

No, it was through the 8010. I pod into 8010 aux. 8010 pre amp to good amp aux. I pod started at no volume to about 1/4. Both amps on. Good amp set to aux. Music played.

 

[Bonvivant25]

8010 controls worked on the music. I could adjust volume, go left and right with speaker channels. Adjust bass, treble ect.

 

[roger2]

Awesome

Now that an entire section of the 8010 is verified good, the remaining sections can be investigated.

 

[Bonvivant25]

I really want to thank you guys!

 

[sregor]

Amplifier section - start by checking for DC - either at the collectors (the cases) of the output transistors or ins 2 and 7 going into the relay/power supply board. If no DC then start trouble shooting relay and protection circuits.

 

[roger2]

I have the tools. I want to fix it myself. I really want to gain an understanding of these types of electronics. I know how to solder. I am handy. I am thinking that I should start with the power supply and protection circuit.

You should have a Service Manual for the 8010. Ideally, make that available to anyone in this thread who may wish to contribute as a convenience, so they don't have to find it on their own...this is just a suggestion of course. Being able to refer to specific things on the schematic makes things go smoother for everyone.

Have you ever worked on live electronics? Are you aware of risks to yourself and to the gear?

Have you read schematics before ?

A good place to check voltages would be where the music signal enters the protection relay. Also, the power supply, both main rails as well as regulated supplies. (DC voltage in all these areas)

 

[roger2]

I'll step back for sregor and pete .. you are in good hands.

 

[gort69]

Does the KR-8010 have plug connectors for the power amp? The fast and dirty way I've narrowed down a couple of KR-7600 repairs has been to unplug both connectors and power it up. If the relay now clicks you can assume the power supply and protection circuits are more or less up to snuff. No click, probably a prob with power supply, relay driver, etc. If the relay does click, power down and plug in one connector, then power up again. If the relay clicks, that channel is good - no click channel bad. Repeat with other plug connector.

All of this is meaningless if this receiver lacks those connectors.

 

[Bonvivant25]

Ok, great stuff here. I have the service manual. I will post it tomorrow because I do not have it at home.

I am aware of the dangers. I have tools to discharge the caps and I use them. I follow the one hand rule when working on live electronics. I have aligator clips and micro clips for my dmm.

Great advice gort. The 8010 does have those removable clips. I removed them all and there was still no relay click. I assume this helps limit the problem to power supply or protection circuit.

Srigor-tested output transistors. The left channel output transistors have approximately 14 mv reading on dmm. The right have -6.8 mv on both.

 

[roger2]

You are more likely to blow something up by a probe slipping than to hurt yourself, although that is possible too. When you say micro clips, do you mean mini alligator-type clips, or mini-grabber type clips?

There will be times when you use the regular pointed DMM probe. If so, it is wise to wrap electrical tape around all but the very end of it. Also, if the tip is dull or rounded off, it can be sharpened with a file, that will help it to grab better and reduce chances of slipping. But use mini-grabbers as a first choice for components legs or test pins.