Yamaha CA-610 II delayed relay

Also what are the voltages I should be seeing at TP2 and TP4?

Ideally 0.00 volts. This is your DC offset -realistically anything less than 50mv is fine. What I'm trying to verify is, if you have rail voltage around 35-40v there. It probably takes a couple volts to trigger the protect circuit.
 
If you go back one page, you'll see what I measured there. 11mV at TP4 and 29mV at TP2. These values never stayed before and after the relay clicked.
 
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A side question, there are two other electrolytic caps I didn't replace, C574 and C576.
These values are:
C574 - 10uF / 25V
C576 - 33uF / 16V

Do you see a problem with replacing them with:
C574 - 10uF / 50V
C576 - 47uF / 25V
 
Using a 47 uf in place of the 33 uf. May change your delay time. You can try it.
 
WOOOOOOOOOOO!!!

C576 did the trick, even with that 47uF in it's place. I took out C574 and measured it, it was dead on so put that one back.

Thanks for your help!!
 
Those 33uf/16 are pretty notorious in yamaha protect circuits.
 
Little violet colored cap with reddish print?..Besides you need the practice.:D

That's the one!

I don't mind the soldering, been doing it off and on for 20 years, but it's been kits where I put together something someone else designed or replace obvious bad components.

Now, is there anything else I should look at replacing while I have it open? I noticed my left channel comes on a second or so after the right, but no static or anything that I can tell.
 
That's the one!

I don't mind the soldering, been doing it off and on for 20 years, but it's been kits where I put together something someone else designed or replace obvious bad components.

Now, is there anything else I should look at replacing while I have it open? I noticed my left channel comes on a second or so after the right, but no static or anything that I can tell.

The rest of the caps perhaps.
 
I know this is an older thread but I am having similar issues .The service manual is not really the most user friendly. First off r408 was burnt out and from what I can see the value is not shown in the manual. My relay does not click on . If I bridge the collector and emitter on tr578 or on tr577 the relay clicks . I did replace c574 and 576 no changes. Does anyone know what the correct value is for r408 is ? and where I should look next to solve the issue?
 
I know this is an older thread but I am having similar issues .The service manual is not really the most user friendly. First off r408 was burnt out and from what I can see the value is not shown in the manual. My relay does not click on . If I bridge the collector and emitter on tr578 or on tr577 the relay clicks . I did replace c574 and 576 no changes. Does anyone know what the correct value is for r408 is ? and where I should look next to solve the issue?
R408 is the same as R407 68KΩ 1/4 watt , carbon film
 
I know this is an older thread but I am having similar issues .The service manual is not really the most user friendly. First off r408 was burnt out and from what I can see the value is not shown in the manual. My relay does not click on . If I bridge the collector and emitter on tr578 or on tr577 the relay clicks . I did replace c574 and 576 no changes. Does anyone know what the correct value is for r408 is ? and where I should look next to solve the issue?
First off we need to verify if there is significant DC voltage at either of the amplifiers output. The protect circuit might be working properly... Check..your DC offset voltage first.........:thumbsup:
 
. Check..your DC offset voltage first.

This measurement will need to be check at a test point before the protect relay. There is a procedure in the SM for checking "Center-point potential " <----- fancy way of saying DC offset.
 
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