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Yamaha A-S701 fried..............help

gad

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My Yamaha A-S701 sits on a low stand under a TV table. I decided that after years the floor and amp could use a dusting. I disconnected all cords and speaker wires, removed the Yamaha and wiped all surfaces with a micro fibre cloth. After dusting under the table I replaced and reconnected the Yamaha, powered on and holy excrement; a really strange sizzling type sound came out of my speaker or speakers and the power light indicator was flickering. Turning it off and turning it back on no weird noises, but the power light flickers and all the source indicator lights start rapidly flashing on and off, then stop flashing and the power light goes to normal. At very low volume it was fine but increasing to moderate volume it shuts down with a flickering power light. I checked and double checked all connections, finally I switched the Yamaha into a bedroom system and installed an Onkyo TX8511 where the Yamaha had been.
Miracle, they both worked fine. So watched some football and this morning switched the amps back to their original systems and the Yamaha failed exactly the same way again. OK,
I put the Yamaha back where it had been working fine just an hour ago and now it fails completely, just a flickering light.

So should I give it a decent burial, or???????????????
 

Chrispy

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Not under warranty any more? Pretty spectacular fail it seems.....or you're missing something in the reconnection setup after it was working fine except for your sanitation?
 

restorer-john

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Sounds like you have a master power relay issue. If you are feeling brave, take off the cover, turn it on and firmly tap the power relay with say a chopstick or knitting needle. No metal screwdrivers ok?

Power relay is the black box on the vertical PCB, top left, just behind the fuse.

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If it bursts into life, you have a failing/dirty set of relay contacts. Basically, that relay connects and powers up the main amp and all the associated circuitry. What you are describing is an unstable set of rails downstream from the wakeup board. The fact it worked perfectly after the first time, means it was/is intermittent.

Also, with the power lead disconnected, check the primary and secondary plug/sockets- unplug and replug them.

Once you have it running at least once, you can run through diagnostics as the unit has a record of historic failures/issues stored. See the A-S701 service manual for details- it can all be done via control settings/button pushes and deciphering the lights.
 
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BDWoody

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Sounds like you have a master power relay issue. If you are feeling brave, take off the cover, turn it on and firmly tap the power relay with say a chopstick or knitting needle. No metal screwdrivers ok?

In all sincerity, I hope you never get tired of this place. I know it has its challenges for you, but you are such an incredible source of actual knowledge, and we are lucky to have you as a regular.

Ok, sappy moment over.

As you were.
 
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gad

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One more moment of sap. Thank you RJ. Boy I wish you had a franchise in Seattle. I have never had a stranger via the internet offer such effort and generosity of their time and knowledge. Being of advanced age with no electronic skills or history I have to assess if this repair is better left to a pro. The Yamaha was bought Oct. 2019 for $485 pre-tax as a refurb on Amazon. Given the scarcity of affordable competent restoration services chances are I will replace. I'm currently listening to my old Onkyo TX8511 and it sounds damn good to my caffeinated brain.

Sincere thanks-
Gad
 

restorer-john

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It'd be a shame for it to go into landfill, they are good amplifiers. Just the other day, I had its baby brother (AS-300) on my bench with a dead channel. Turned out to be a tiny, corroded-through track on the PCB. That amp is now being 'auditioned'* at my dad's place.

*auditioned is an excuse for me lending my 89yo dad another HiFi toy to play with.
 
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restorer-john

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Ixnay on the knitting needles. What do they make them out of in Australia, shark's teeth?

Most are plastic in my experience, but some have metal inside the plastic. Not being a knitter, I should have clarified as metal ones would be a bad idea.

I often pick up the plastic ones from thrift stores for a few cents and file/shape the end to make specialized slug/pot adjustment tools. Very good for getting down into say a vertical amp driver board to adjust bias and offset. Often out of reach of my shorter dedicated adjustment tools.

A bamboo chopstick is also a very good poking tool.
 
OP
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gad

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@gad what was the outcome?
Currently I am satisfied with my old Onkyo integrated. I got frustrated trying to find a local repair facility and with no warranty shipping to a Yamaha repair facility makes no financial sense. I'm considering my current topping D90 dac -> nobsound mini fully balanced passive preamp -> hypex nc252mp. Fear of the unknown has delayed this purchase. To morph the classic Jack Nicholson line from A Few Good Men into audiophile terms, "you can't handle transparency." I worry that I will miss bass/treble/balance controls and that adding dsp or a feature rich preamp puts me out of the AS701 price bracket.

gad
 
OP
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gad

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OP update. Well it's been a while. With new info that there is or will soon be a next model replacement for the AS701 I've been checking Amazon.com USA for a price reduction. This morning I ordered the silver AS701 for $671.96. At that time the black was $743.95. Now black and silver are both $743.95. That's still less than the original $799.99. Obviously for whatever reasons there are momentary price drops. The one I ordered is new.
 

Doodski

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OP update. Well it's been a while. With new info that there is or will soon be a next model replacement for the AS701 I've been checking Amazon.com USA for a price reduction. This morning I ordered the silver AS701 for $671.96. At that time the black was $743.95. Now black and silver are both $743.95. That's still less than the original $799.99. Obviously for whatever reasons there are momentary price drops. The one I ordered is new.
Veryyy nice. New shiny Yamaha coming soon. :D
 
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gad

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Let's hope it is new.

;)
Do we ever know? Having been burned with a refurb purchase I am a believer in reasonable due diligence. The invoice states, sold by Amazon.com Services LLC, condition NEW. Per the Yamaha website amazon.com is an internet authorized distributor hence 2 yr. Yamaha warranty applies. Suspicious me called a
Yamaha authorized service center and asked if Amazon.com Services LLC was a covered authorized dealer and was told yes the Yamaha 2 yr. warranty applies.
 
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