Yamah Amp Problem

darthy · 15th August 2008, 01:23 AM

My vintage Yamaha Integrated Amplifier CA-610 II takes approx. 2 MINUTES before the relay clicks and sound is produced. I have cleaned the switches/controls and looked over the board . Any suggestions are appreciated

Mooly · 15th August 2008, 07:23 AM

Circuit !!! Failing that, measure the output offset voltage on each channel before the relay. If it's OK, it's possibly a problem with the protection circuit itself.
Also check for dry joints throughout but particularly ANY power transistor anywhere in the amp & PSU etc, older Jap stuff is terrible for this problem, and when you try and resolder you find the solder "won't take".
Remember the relay is either "telling" you there is a problem with offset voltage or the protection circuit itself is misbehaving. Checking the offset voltage will confirm which it is.
My moneys on a DJ or very unlikely, a transistor that is intermittant open circuit, which is another weird affliction of Jap transistors.
Good luck

darthy · 16th August 2008, 10:01 AM

If I shut the ampoff, then immediately turn back, on it only takes a few seconds before relays clicks open. Does this sound like something "other" than protection relay??

Mooly · 16th August 2008, 10:39 AM

Hi,
Impossible to say. You have to take measurements to at least isolate which area the fault is in, even if you don't know how to fix it. A dry or intermittant transistor would certainly behave as you describe.
Do you know what we mean by "offset voltage" as that's the first thing to check when any protection circuit keeps the speakers disconnected.

megajocke · 16th August 2008, 11:23 AM

It could be an electrolytic cap in the power on mute circuit that has gone bad. I'd start by checking DC offset on the output of the power amp before the relay to narrow the problem down.

djk · 16th August 2008, 09:49 PM

http://www2.yamaha.co.jp/manual/pdf/...ntA/CA-610.pdf

Start with replacing the timing cap for the relay, C461.

darthy · 21st August 2008, 08:43 PM

I checked DC Offset at speakers and I get 5.1mv and 3.3mv. I am reluctant probing on the board with unit "powered ON". Is there any other test I can perform or should I just buy new capacitors and replace and hope? According to the shematic, there is about 33 electrolytic caps. Do I need to replace ALL of them? Maybe I have a bad transistor too?

djk · 21st August 2008, 08:59 PM

At the risk of repeating myself:

"Start with replacing the timing cap for the relay, C461."

Leolabs · 22nd August 2008, 01:59 AM

Check for leaky caps,cracked solder joints.

unclejed613 · 22nd August 2008, 03:29 AM

actually you want to check for the DC offset at the output inductor on the amp board.

15th August 2008, 01:23 AM	#1
darthy diyAudio Member Join Date: Aug 2008	Yamah Amp Problem My vintage Yamaha Integrated Amplifier CA-610 II takes approx. 2 MINUTES before the relay clicks and sound is produced. I have cleaned the switches/controls and looked over the board . Any suggestions are appreciated

16th August 2008, 09:49 PM	#6
djk diyAudio Member Join Date: Feb 2001 Location: USA	http://www2.yamaha.co.jp/manual/pdf/...ntA/CA-610.pdf Start with replacing the timing cap for the relay, C461. __________________ Candidates for the Darwin Award should not read this author.

21st August 2008, 08:59 PM	#8
djk diyAudio Member Join Date: Feb 2001 Location: USA	At the risk of repeating myself: "Start with replacing the timing cap for the relay, C461." __________________ Candidates for the Darwin Award should not read this author.

22nd August 2008, 03:29 AM	#10
unclejed613 diyAudio Member Join Date: Dec 2006	actually you want to check for the DC offset at the output inductor on the amp board. __________________ Vintage Audio and Pro-Audio repair ampz(removethis)@sohonet.net spammer trap: spammers must die

Thread Tools	Search this Thread
Show Printable Version Email this Page	Search this Thread: Advanced Search


	Please consider donating to help us continue to serve you. Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving

15th August 2008, 07:23 AM	#2
Mooly diyAudio Moderator Join Date: Sep 2007	Circuit !!! Failing that, measure the output offset voltage on each channel before the relay. If it's OK, it's possibly a problem with the protection circuit itself. Also check for dry joints throughout but particularly ANY power transistor anywhere in the amp & PSU etc, older Jap stuff is terrible for this problem, and when you try and resolder you find the solder "won't take". Remember the relay is either "telling" you there is a problem with offset voltage or the protection circuit itself is misbehaving. Checking the offset voltage will confirm which it is. My moneys on a DJ or very unlikely, a transistor that is intermittant open circuit, which is another weird affliction of Jap transistors. Good luck

16th August 2008, 10:01 AM	#3
darthy diyAudio Member Join Date: Aug 2008	If I shut the ampoff, then immediately turn back, on it only takes a few seconds before relays clicks open. Does this sound like something "other" than protection relay??

16th August 2008, 10:39 AM	#4
Mooly diyAudio Moderator Join Date: Sep 2007	Hi, Impossible to say. You have to take measurements to at least isolate which area the fault is in, even if you don't know how to fix it. A dry or intermittant transistor would certainly behave as you describe. Do you know what we mean by "offset voltage" as that's the first thing to check when any protection circuit keeps the speakers disconnected.

16th August 2008, 11:23 AM	#5
megajocke diyAudio Member Join Date: Jan 2003	It could be an electrolytic cap in the power on mute circuit that has gone bad. I'd start by checking DC offset on the output of the power amp before the relay to narrow the problem down.

21st August 2008, 08:43 PM	#7
darthy diyAudio Member Join Date: Aug 2008	I checked DC Offset at speakers and I get 5.1mv and 3.3mv. I am reluctant probing on the board with unit "powered ON". Is there any other test I can perform or should I just buy new capacitors and replace and hope? According to the shematic, there is about 33 electrolytic caps. Do I need to replace ALL of them? Maybe I have a bad transistor too?

22nd August 2008, 01:59 AM	#9
Leolabs diyAudio Member Join Date: Dec 2004 Location: Bukit Mertajam	Check for leaky caps,cracked solder joints.

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
UGS Problem	Ian Macmillan	Pass Labs	44	14th November 2009 10:52 AM
another BOZ problem....	rtate	Pass Labs	8	11th July 2008 06:51 PM
I need help with a pot problem.	Harderror	Class D	8	16th December 2006 04:04 PM
Yamah p2200 setting idling current	priscared	Solid State	11	14th August 2004 01:39 AM

New To Site?	Need Help?
Register to Participate Search Privacy Statement Contact Us	Frequently Asked Questions Did you forget your password? Mark Forums Read