Kenwood kr-9600 problem

ducati2

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I just acquired a beautifully clean kenwood kr-9600. All the lights work and everything seems in place but no output in fm or aux or anywhere. Only indication I can see that is positive is the tuning meter moves a little while channel surfing, but the signal strength meter is dead zero.

All the top fuses are good. Anything common an simple i am missing? Where do I go from here?
 
to the bottom fuse(s)?
Is the tape monitor switch in the right position?
Does that model have separate preamp and power amp? If so are the pre out and main in jacks connected?
Those are the commonest and simplest.
 
brute

Man, that's a big brute.
Never poked around in one but I'd bet it has a protection circuit.
Do you hear a "click" shortly after turning it on? (1-5 seconds).
If not, its in protection mode and needs service. (probing and soldering).
 
Man, that's a big brute.
Never poked around in one but I'd bet it has a protection circuit.
Do you hear a "click" shortly after turning it on? (1-5 seconds).
If not, its in protection mode and needs service. (probing and soldering).


no CLICK ,, just all lit up with no sound. so how do I get it out of protection you think? hmm. fyi- I am new to SS, mostly work with tubes.
 
to the bottom fuse(s)?
Is the tape monitor switch in the right position?
Does that model have separate preamp and power amp? If so are the pre out and main in jacks connected?
Those are the commonest and simplest.


yes, the pre-out and main-in are connected via jumpers. I also pulled the jumpers and deoxit the area - then reinstalled.

yes - tape monitor was tried in all positions.
 
just a follow up, there is no click after turning on the unit and no power other than the lights looking great. Tuning meter moves a little, but no sound from FM , phono or aux, etc.

here is a list of what I have done so far ;

clean the unit and visually check for anything that looks toasted -none found
deoxit (twice) on all switches and controls
checked all fuses - 5 on top and 1 underneath
checked for jumpers - they are there
checked for monitor and speaker switch to be in correct position
cleaned jumper terminals w deoxit
checked voltage on pins 1-10. results as follows -
pin 1 = 0v
pin 2 = 67v
pin 3 = 67v
pin 4 = 0v
pin 5 = 0v
pin 6 = 0v
pin 7 = 0v
pin 8 = 67v
pin 9 = 67v
pin 10 = 0v

ANY SUGGESTIONS ON WHAT TO DO NOW? PART IT OUT???? fyi - I am new to SS.
 
Well, you have the correct voltages, according to the manual. Are the relays engaging?
BTW, the service manual is downloadable at Hifiengine, if you don't have one.
 
Well, you have the correct voltages, according to the manual. Are the relays engaging?
BTW, the service manual is downloadable at Hifiengine, if you don't have one.

no click, so I guess the relays are not kicking in. I just downloaded the service manual and will try to locate the relay. I don’t suppose the relay itself would be the problem, could it? Or rather if the relay does not engage, does that mean there is another problem causing that? I suppose could clean the relay and hope for the best.
 
Hello,

You have a troubleshooting tree in the service manual.

You should first check the power supplies, pins 3 & 5 of the power amp board, +/- 67V

You should also check output voltage, pin 6, about 0V, at least less than 50mV.

Regards.
Alain.

oops, already answered !!

You should check the reed relay voltage, pin 11, on the power supply board, 10V.
 
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no click, so I guess the relays are not kicking in. I just downloaded the service manual and will try to locate the relay. I don’t suppose the relay itself would be the problem, could it? Or rather if the relay does not engage, does that mean there is another problem causing that? I suppose could clean the relay and hope for the best.

The relays operate as part of the protection circuit. They are probably doing their job. Besides checking operating voltages at the transformer secondaries and through the circuits, checking for DC at certain points is probably advisable. I will have to look at the service manual and the 9600 that is on my bench before I can advise any further.

Your problem could be as small as a failed capacitor or both of the output amp packs failed. Hope for the former :yes:.

I believe there were a few theads about the KR-9600 and trroubleshooting where Echowars has contributed. A search for those might help.
 
the troubleshooting guide in the service manual says to first verify the power relay is working. All I know is they do not click when powered up. Should i pry off the clear plastic containers and probe around or something? Or should I just try to order replacements?
 

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The relays operate as part of the protection circuit. They are probably doing their job. Besides checking operating voltages at the transformer secondaries and through the circuits, checking for DC at certain points is probably advisable. I will have to look at the service manual and the 9600 that is on my bench before I can advise any further.

Your problem could be as small as a failed capacitor or both of the output amp packs failed. Hope for the former :yes:.

I believe there were a few theads about the KR-9600 and trroubleshooting where Echowars has contributed. A search for those might help.

thanks for the clarification westend, This unit was stored for possibly 25-30 years, do you think the relays could possibly be stuck with minor corrosion? They look brand new, but just wondering.
 
i have read that the kr9600 relay not clicking on can sometimes be due to bad transistors on the power supply (A) board. It was recommended to check the voltages and I did so, however I know very little about transistors, so not sure what to do with the info.


v on left pin / v on middle pin / v on right pin

Qk 10 = 0.2/30.1/0
Qk 11 = 0/0/1.7
Qk 12 = 0.6/0/0
Qk 13 = 0/67/0
Qk 14 = 67/0/67

anyone know what this should mean to me? do I need to replace a transistor?
 
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First, use the preouts into a good amp and see if you get output. This is the first step. If that works, you can move forward with the amp section.

The KR-9600 in my experience has a common problem with DC tripping the protection circuit and there are many posts here about the work required to make this right. As mentioned here, do hope that the amp modules are not fried.

To measure DC at each amp, I don't recall the exact wiring color, but if you pull the bottom cover and look on each amp board, you will see a yellow or blue wire and it's return, possibly black, that runs to the speaker switch or the relay, forget which one. Anyway, you can measure DC there. Once you get into it it should be obvious that this is the amp's output. Check that and report back. If you want to possibly sacrifice a speaker, you can wire that up and see if you get output, but don't use anything you don't care to fry...:D
 
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First, use the preouts into a good amp and see if you get output. This is the first step. If that works, you can move forward with the amp section.

The KR-9600 in my experience has a common problem with DC tripping the protection circuit and there are many posts here about the work required to make this right. As mentioned here, do hope that the amp modules are not fried.

To measure DC at each amp, I don't recall the exact wiring color, but if you pull the bottom cover and look on each amp board, you will see a yellow or blue wire and it's return, possibly black, that runs to the speaker switch or the relay, forget which one. Anyway, you can measure DC there. Once you get into it it should be obvious that this is the amp's output. Check that and report back. If you want to possibly sacrifice a speaker, you can wire that up and see if you get output, but don't use anything you don't care to fry...:D

I have voltage all the way to both relays, just not after. Output from left side amp to relay is 62.5 v dc and right side to relay is 56.7 v dc. Is that enough difference to trip the relays? oh. just thought of something, not sure I had the balance knob in the middle, would that affect my reading?

I have never run an amp through another amp, that is how green I am. I suppose I pull the jumpers and output from the 9600 to an input of another receiver? Just through the AUX input?? Or, does it need to be a receiver with the similar jumper set up? Sorry for the dumb questions.

getting more determined to FIX this thing.
 
You want to run the preamp outputs to another power amp or you could run them to any low level (not phono) input to another receiver or integrated amp, using the front end of your KR-9600 as the "source".

Make sure you test it with the volume up high enough on the 9600. Should you be able to output the tuner normally, you have isolated the problem to the amp.

To measure DC, which is what is likely tripping the protection circuit, you want to measure right before the relay. I don't have a schemo handy but I recall getting the measurement off the yellow and blue amp leads, right at the PCB for each amp. DO consult the schematic for the appropriate wires. If you are in fact getting 50-60 VDC from the speaker leads pre relay, you indeed have big problems. Echowars is the resident expert on the KR-9600 (and just about everything else!) and will no doubt chime in here with specific procedures shortly. Hang in there :thmbsp:
 
What Bigears is helping you to determine is if a problem exists in the preamp or the poweramp. What we are trying to do is isolate the problem by elimination. By separating amp input from the preamp out put on the back of tha amp (jumpers out), taking a pair of RCA phono interconnects and hooking them to another power amp from the preamp output of the KR9600, and determining if there is sound, we can determine if the problem is in the preamp (or associated circuits) or the power section of the 9600. Capiche? If you have another amp, this is easy to do.

If you don't have another amp but have a CD player, you can hook the interconnects from the CDP output to the 9600 "power in" input. If you do this, measure for both AC and DC voltage at the speaker terminals (+,-). I'm guessing you will see no voltages. If you have a small amount of varying AC voltage, it would indicate that the power amp section of the 9600 is OK. If you have any DC voltage over 100 mv, you have other problems or the amp needs adjustment.

All for now, my keyboard repair to the "r" key is not working on my keyboard. Do you want to see how this post would have been with out a lot of rrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrecoverrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrry backspacing? :D
 
You want to run the preamp outputs to another power amp or you could run them to any low level (not phono) input to another receiver or integrated amp, using the front end of your KR-9600 as the "source".

Make sure you test it with the volume up high enough on the 9600. Should you be able to output the tuner normally, you have isolated the problem to the amp.

To measure DC, which is what is likely tripping the protection circuit, you want to measure right before the relay. I don't have a schemo handy but I recall getting the measurement off the yellow and blue amp leads, right at the PCB for each amp. DO consult the schematic for the appropriate wires. If you are in fact getting 50-60 VDC from the speaker leads pre relay, you indeed have big problems. Echowars is the resident expert on the KR-9600 (and just about everything else!) and will no doubt chime in here with specific procedures shortly. Hang in there :thmbsp:

ok, I think I don’t have any sound, but help me verify if i did it right.. I hooked up rca cables from the pre out on the 9600 to the ‘power in’ on my kenwood 5150 and tried to play my ipod via the aux on the 9600 - nothing coming from the speakers on the 5150. Then, I also did the reverse. I ran the cables from the output on the 5150 to the input on the 9600 with the ipod still on the aux at the 9600. No sound coming from the 9600 speakers.

ONE question, the 5150 has a switch (in photo) that I never knew what is for,, “normal or separate”. I had it on normal. Do i need to switch it to separate??
 

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ONE question, the 5150 has a switch (in photo) that I never knew what is for,, “normal or separate”. I had it on normal. Do i need to switch it to separate??

Yes, you must have it switched to separate for this to work. Try it again and post the results.
 
Yes, you must have it switched to separate for this to work. Try it again and post the results.

ok, flipped the switch to separate and re-ran the test as described - still nothing, not even a hum or crackle. I tried all variations I could think of.

So, what do you suppose this means?
 
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