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Yamaha A-760, A-760II, A-960, A-960II, A-1060, M-50, M-70 and B-6 @ 220-240V warning!

R

rdeck

AK Veteran
Official URL
*maybe a good idea to have a seperate forum for these kinds of messages

Safety Information

Yamaha Amplifiers (Years of construction 1980-1982) for European models, using 220-240VAC line voltages (This information does not apply to 120VAC models)

Models A-760, A-760II, A-960, A-960II, A-1060, M-50, M-70 and B-6

Yamaha products have a reputation for maximum reliability and durability.
Analysis of servicing data and our quality assurance system have revealed a potential safety risk which necessitates switch-off of all relevant models currently in operation. The models affected are A-760, A-760II, A-960, A-960II, A-1060, M-50, M-70 and B-6.
These amplifiers are now between 25 and 27 years old.

Model name is printed on the Front panel.

The models listed above contain a component in the power supply assembly, which can in very rare cases suffer damage. This can be followed by significant emission of smoke and can in some cases even cause fire within the amplifier.
As a risk precaution, you should disconnect the amplifier from the power supply by removing the plug..

Please contact us

09.00 – 17.00 Tel. +49 (0) 4101 309 168

Email: service@yamaha-online.de

before reconnecting the amplifier and using it again.
 
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No, it's the big paper-oil capacitor for noise suppression in the power supply. They detonate, which can be a very impressive encounter.
 
LOL I picked up an M-70 that has suffered this "explosion". I also have an M-50 with the same power supply set up!
 
So, it should be replaced with an X2 or something?

A-760 board pictured below.
 

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Yes, am X2 would be OK. Before one LOL's - I got one B-6 from eBay two years ago where this cap had detonated. It was a terrible mess inside, a large area of the chassis and the pcb was covered with a black, sticky and corrosive stuff. The neighbourhood of the cap was severly burnt. This security warning is serious.
 
Yes, compared with the layout of a B-6 in your amp it should be C501. It is a 0,47 µF/250V paper-oil-cap. BTW it was not so hard to find a replacement cap, merely 70 cent or so.
The guy who sold the B-6 to me denied any strange smell or noise coming out of the amp. This is something I cannot believe when I see the picture (attached).
 

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Looks exactly like the component that failed in my sony tuner, a bang and the foulest smell I have ever smelled. Good thing I caught it when it happened. Also, the unit was switched off...
 
Well I picked up a Yamaha M-70 amp today, cleaned it up then plugged it in and it popped so loud and scared the crap out of me. Then it started smoking. I turned it off and unplugged it. I looked inside and seen the still smoking paper oil cap. I searched AK and found this thread. Has anybody emailed Yamaha about this? What do they do about it? Is this paper oil cap easy to find? Thanks for any help or info on this. N8
 
n8thesk8 said:
Well I picked up a Yamaha M-70 amp today, cleaned it up then plugged it in and it popped so loud and scared the crap out of me. Then it started smoking. I turned it off and unplugged it. I looked inside and seen the still smoking paper oil cap. I searched AK and found this thread. Has anybody emailed Yamaha about this? What do they do about it? Is this paper oil cap easy to find? Thanks for any help or info on this. N8
Click to expand...

Well, if you read the thread, it seems that replacing the cap with the same type os cap isn't ideal. An X2 capacitor might be a better choice.
 
Thanks Martin.Ca. I guess what I need to find out is how to identify the correct part and were to get it from. I emailed Yamaha and no response yet. N8
 
An older thread, but...

Even though Yamaha's warning is said to only apply to the European versions, would it be a good idea to be proactive and replace the cap on the 120VAC versions as well?
 
Enquiring minds want to know if the 120V version could also be suspect! I just picked one out of a free pile in front of a house yesterday......
 
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sandoz said:
Enquiring minds want to know if the 120V version could also be suspect! I just picked one out of a free pile in front of a house yesterday......
Click to expand...

Quoting the URL in the OP: "Yamaha Amplifiers (Years of construction 1980-1982) for European models, using 220-240VAC line voltages (This information does not apply to 120VAC models)"
 
Yes, the URL states that, but I have known companies to say one thing in one country and not in another even if both are affected. This is reason enough to wonder if you ask me.

Prime example? I drive a Toyota Yaris. The car is the same in both the US and Canada, but the manual gives a towing capacity for Canada and says not to tow at all for the US.
 
sandoz said:
Enquiring minds want to know if the 120V version could also be suspect! I just picked one out of a free pile in front of a house yesterday......
Click to expand...

Mine is the 120v version and it went up in smoke. 6 bucks for the part from Yamaha and about 15 minutes of work and good as new. N8
 
Has anyone found a good source for these caps? I checked parts express, digi, mouser, and parts connexion, but I MAY just be parts-search retarded. What should I be searching for, specifically. I mean, I found .47uf 250v non-polars, but I don't think that's what is required, right? Any ideas?
 
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