• The move to the new server is done. There are some software and database maintenance updates in process. This has us passing the hat around to help out. We appreciate any donations. Seriously, even a dollar helps. The payment page may be found here - https://www.audiokarma.org/support.html

Yamaha CA-610 II Speaker Relay

ScooterMcTav

ScooterMcTav

I know less than I think
Hello all,

Found the above mentioned receiver at the local electronics recycler, and was hoping to get it fired up to test head-to-head against my Sony STR-5800.

When doing initial checks (power on, and DC offset checks), I did not hear the normal noise of the speaker relay switching on, and I had zero DC at the speaker terminals. Also tried toggling the speaker switch off and on, and still no speaker relay click.

A couple of taps with the handle of my screwdriver, and again, no relay click.

I performed a detailed visual inspection of the unit, and saw no obvious signs of a failing part, nor any bulging or leaky caps.

Both visible fuses were removed and checked for continuity, which they passed.

Possibly related, there was also no light on the VU meters.

Suggestions as to where to look next? Anyone else had similar issues?

Thanks all in advance.
 
Register to hide this ad
With the relay open you won't get any connection from the power amp to the terminals so no matter what happens before the relay it won't be measurable at the posts.
You can open the receiver up and ground one DMM lead and use the other to test the input pins of the relay and see if you have any DC present there. If so you have a power amp issue.
If no odd voltage is found at the relay pins, measure both coil pins of the relay to see if you get voltage at both. If so then something is causing the protect circuit to fail to ground the coil which would close it (if the circuit is closed you'd have voltage at one pin and none at the other).

Once you figure out where the problem is you can start to do some more specific diag.

The service manual for your unit is here: https://www.hifiengine.com/manual_library/yamaha/ca-610.shtml
You'll have to sign up but they don't ever bother you for anything again so it's safe.
 
1. Shorted output transistor(s)
2. Power supply malfunction
3 Protect circuit malfunction.
 
Greetings friends,

This is an old post but I hope to piggy-back on it because I have a near identical situation and I was hoping for clarification and assistance. Actually there are a few 610 II relay posts but I hope this one will work. If perhaps a new post would be more appropriate I'm happy to do so.

Protection Relay will not engage:
I can manually close the protection relay on my 610 and it plays, so I'm fairly certain my issue is the protection circuit itself. My question pertains to TR574 which is also called out in the relay test diagram for the protection circuit.

1. Is a KSC1845 a good substitute if in fact TR574 (2SC1918) has failed
2. If TR574 is OK is there another "most likely" failed or faulty component in the protection circuit -

I'm having trouble identifying exactly which components are part of the protection circuit since they don't seem to be segregated onto their own board, if you will.

s1.png


p1.png

Thank you in advance for any assistance or recommendations.
 
Protect circuit --- TR574 , 575 ,576 ,577 & 578

Check and post your ECB voltages around 577 and 578 .
 
Post a topside photo of the general area of the above transistors.
 
US7IGN said:
I see a lot of old lytics around and... what? What the hell are those old Soviet red resistors doing there?
Click to expand...
Yes, this unit definitely needs a good re-capping... as far as the 10ohm red Soviet resistors, I had no idea they were of Russian origin?
 
FYI...Before I posted this issue I researched as many 610 II relay issues as I could find. And some relay issues I read about were due to fuse-able resistors in the protection circuit having failed. The red resistors were the first components I checked and they appear to be healthy.
 
I would replace D579, 580 and C583, 584. The fuse resistors are supposed to protect other elements and I would strongly recommend replacing them with the correct ones. If everything works correctly, then do a complete normal restoration.
 
9 volts on the base of TR574.... Massive DC voltage on the output of the left channel... Are you sure the left channel works. If it does. Then your measurement is incorrect.

With 9 volts on the base of TR574 the protect circuit is doing what it is suppose to do. The amplifier is in protect mode.
 
avionic said:
9 volts on the base of TR574.... Massive DC voltage on the output of the left channel... Are you sure the left channel works. If it does. Then your measurement is incorrect.

With 9 volts on the base of TR574 the protect circuit is doing what it is suppose to do. The amplifier is in protect mode.
Click to expand...
Thanks. I will manually set the relay again and see if in fact I have both channels. I did check each value twice when measuring so if the values I provided are correct it may indicate - as you state - L channel may very well be out.
 
So after manually holding down the relay again both channels do in fact work?? The output meters show good output. I re-checked and re-checked again the high voltages and they are now ~29V but still high. I'm only keeping the relay closed for about 10-15 seconds but when closed everything looks and sounds good/normal with speakers and/or headphones.

Since the 9 volts confirms the protect circuit is working wouldn't it be logical to assume the origin/source of the ~29V is the problem? I don't really understand so forgive me.

I may have taken a risk to connect speakers if there were DC going them but that doesn't seem to be the case. At this point I don't even know how much DC may be going to the output but it doesn't seem like there could be much based on the tests and the way it sounds when relay engaged.

Would it be time and cost effective to simply replace the core components of the protection circuit? (I was one told there are no stupid questions, that could have been a liemeasure point TR577.jpg.)
 
You must log in or register to reply here.
Back
Top Bottom