CA-610 II Powers up, No sound

[bktheking]

Well I'm on the road now and can't look at the circuit, diodes resistors caps???lol take bce measurements and post them, maybe avionic will see and reply.

 

[craxx6969]

Well I'm on the road now and can't look at the circuit, diodes resistors caps???lol take bce measurements and post them, maybe avionic will see and reply.

I've checked all of the transistors, pulled them from the board, using the method Echowars penned over in the Pioneer forum. None of them are shorted or open. I replaced one cap, C500, which is a 1uf/50 volt which did not resolve the issue. I have not taken anymore readings as i was gone this afternoon. I am back to find the culprit..

 

[craxx6969]

I've checked all of the transistors, pulled them from the board, using the method Echowars penned over in the Pioneer forum. None of them are shorted or open. I replaced one cap, C500, which is a 1uf/50 volt which did not resolve the issue. I have not taken anymore readings as i was gone this afternoon. I am back to find the culprit..

Anyone have a caps list for this machine? I plan on replacing most of the transistors and caps which should rectify the bias issue on the right channel. It would be nice to start a caps sticky for each machine that is done with the help of the board members. That way new members can be referred to those stickies rather than going over them again and again. One can always post the list before ordering so they can be vetted out.

Just a thought.

Thanks,
JT

 

[bktheking]

Man would life be easy for a cap list for every yamaha unit, got one for a cr3020???

 

[avionic]

Anyone have a caps list for this machine? I plan on replacing most of the transistors and caps which should rectify the bias issue on the right channel. It would be nice to start a caps sticky for each machine that is done with the help of the board members. That way new members can be referred to those stickies rather than going over them again and again. One can always post the list before ordering so they can be vetted out.

Just a thought.

Thanks,
JT

You have the best cap list source sitting on your bench.

 

[avionic]

Man would life be easy for a cap list for every yamaha unit, got one for a cr3020???

Shitload....

 

[4seatPilot]

Shitload....

I can't find that BOM or project on mouser

(that was a joke)

sent from the galaxy 2 with tapatalk

 

[craxx6969]

Checked all values at each transistor on the right and left channels. Still cannot get the dc offset dialed in on the right channel. Output transistors are okay. Any suggestions.

You should start your own thread 4seatpilot.

 

[avionic]

Still cannot get the dc offset dialed in on the right channel

I'm assuming you meant bias or idle current. Not DC offset.

 

[4seatPilot]

You should start your own thread 4seatpilot.

If I had questions, I would. But I don't.

 

[craxx6969]

I'm assuming you meant bias or idle current. Not DC offset.

Yea, sorry late post. I have checked the voltage on all the TR's in both channles and they are all within spec EXCEPT TR501 and TR502. The voltage on the base should be a -0.3, mine show + 0.535. I checked the two FR resistors in those circuits and they are both at 220 ohms. I also checked the 4.7 resistors in that circuit and they are also with spec. The differential voltage as measured from E to the TP's are not within the 0.1v spec. I do have both channels working but without being able to set the idle current I cannot release the amp back to our friend.

Any help on this would be greatly appreciated..

thanks in advance.

 

[mbz]

I also checked the 4.7 resistors in that circuit and they are also with spec.

Just a footnote in an old thread.

Had similiar problems, turned out to be one of those 4.7ohms output base resistors.
The resistors are in a cover, one showed some heat stress. In circuit measurement
gave "in-spec". After removal the resistor fell to pieces, was badly charred.