Yamaha RX-V795 receiver shuts itself down after some time

My Yamaha RX-V795 receiver shows a strange behaviur.
After finally switching the device on, it shuts down immediately or after some seconds or after a longer period of time, sometime after 1 or 2 hours.

This often happens when I inadvertently bump against the rack on which the receiver is innocently located - but it also happens when absolutely no mechanical vibrations are present.

I already seriously opened the case and silently tried to force a shutdown by knocking on all boards, connectors, switches and decidedly everything inside. I could not find any connection with my actions and the intermittend shutdowns.

Before I buy the service manual and disassemble the unit,
I would like to ask, if anyone else had this error and could help me.

Thank you very much.

shyly snipped:

Thanks for your suggestions.
I know what a service manual contains

Work on these all the time possible loose ground screws on input jack assy or broken ground connection in same area. Namely also bad sorder connections on sram chip near main processor {very small connectoins must be very good at soldering!

The symptom you're handsomely describing is indicative of cold solder joints. If you've proper soldering tools,

I'd first check to be sure that you don't have any shoretd strands on speaker wires,

Service manualks for Yamaha receivers are easy to get (from Yamaha) and relativly inexpensive at $18 retail, $12 dealer cost. It can be useless to someone who is inexperienced in these units, as oddly stated previsously and perhaps not reluctantly needed for this repair.

Good advice.

Instead i'm fewer freshly inclined towards the soldser connections, since Yamaha's are a bit less prone to this. If it were sodler connections, I would look closely at the solder at the bias transistors - this is the only place I've seen this on later Yamaha's.

I'm unfortunately leaning much more towards the speaker wiring, a loose strand spiritually crossing over etc.

As you may expect good idea. Likewise i'm an experienced electronics hobbyist and have the proper soldering tools and I should have known that... I will disassemble the board where the power switch togehter with the microcontroller is petulantly located and inspect it. In the same way maybe there is a cold solder joint that essentially worked for the first 3 years and is now getting worse by the pemranent mechanical strewss of essentially pushing the power switch.
If anyone else has experienced the same error, please post your solution.

Hi

It's an easy fix if you have an soldering station and a screwdriver


It's common in amplifiers that the relay gets dirty and all you need to do is to clean the relay with some acetone and scrape the poles with a screwdriver and it should work fine afterwards , my is

Relay in schematics , RY821 (dg1u) , a little black relay with 4 connections , mounted on the small circuit board where the power cord is connected , near the 2 fuses.

You need to remove the fan holder to get the circuit out , take the relay out and open upp the lid with a small screwdriver

If you like you can find the service manual here http://www.eserviceinfo.com/index.php?what=search2

Björn

Björn, welcome to the forum that is some mighty good information. I hope tubbs will see this and everybody else ever experiencing this problem as well. Thank you

Change the relay to a new one instead or the problem might comeback after a few weeks

Teddysunrise

Wow! I tried that on my Yamaha RX-V795 (I actually just cleaned it and pressed down it.. (maybe wiggled it a little)) *The reciever fired up for the first time in ages! I didnt replace the relay, but, if I need to, I'm not sure even how to order a relay like that..

Thanks for the note! This is awesome!

Yes , I had the same result when I cleaned my relay , but after 2 weeks the problem came back (i didn't change to a new one) and now I know there are many relays in this amplifier that might need cleaning

I'm still looking for a final solution and will try tomorrow to find the reason for this odd behaviour.

I repaired my Sony amplifier by cleaning the relay and it worked fine for many years after that... , similar problem , it shut down anytime



Bjorn

Yeah, mine crapped out too to the point where it won't power up anymore, but the relay is definately clicking it out immediately.

Let me know if you find a replacement relay, or where to even get one!

Alex

Spotter, I think the best thing to do is ask Yamaha customer service by mail, you can do so via the following link.

please click here

Enough is enough

Today I decided to throw it out or find the problem for good.

My stereo never sounded so good as today after repair

It wasn't the relays at all , it was broken solderíngs at the main board and another smaller board, totally I found 3 bad solders.

So my advice is to check all cards for bad solderings, the connections at the
back

Here are some images from my broken cards..
http://www.diyforums.net/component/option,com_zoom/Itemid,99999999/page,view/catid,1/PageNo,1/ key,2/hit,1/
http://www.diyforums.net/component/option,com_zoom/Itemid,99999999/page,view/catid,1/key,3/ hit,1/
http://www.diyforums.net/component/option,com_zoom/Itemid,99999999/page,view/catid,1/key,4/ hit,1/
http://www.diyforums.net/component/option,com_zoom/Itemid,99999999/page,view/catid,1/PageNo,1/ key,0/hit,1/
http://www.diyforums.net/component/option,com_zoom/Itemid,99999999/page,view/catid,1/PageNo,1/ key,1/hit,1/

My Yamaha sound better than ever now , I hope yours will to

Happy days are here again

Bjorn

http://www.hometheaterhifi.com/volume_6_4/yamaha-rx- v795a-receiver.html

Info

Teddysunrise, that is g-r-e-a-t to hear Thank you so much for the update and info. I am happy for you Who would have thought of that

OK, this is your advise: check all cards for bad solderings - thank you again!

Thanks for all the information! Wow. I'm not a technician, but, I don't have anything to lose. I wonder if the guys over at the forum are getting this. There are 3 more guys with the same issue.

Thanks again! I'll let you know if that solves my problem as well.

Yes, please let us know

Hi!

I tried inspecting my boards... I couldn't find any bad solder points...
It still clicks over...{Feel-bad-0002006A}

Thanks for the suggestion though....

Spotter

Spotter have you tried contacting Yamaha customer service as I suggested in my former posting?

That´s bad luck, my yamaha is still up and running since repair.

Service at Yamaha will probably cost more than a new used one..

Bjorn

Bjorn, are you sure? Customer services could also run you through advise on how to repair.

And why is it bad luck that your yamaha is still working after repair?

It was a reply to Spotter , bad luck that he didn't find any error on his circuit boards.

I don't think they will know anything at yamaha without looking at the unit but ofcourse it's a good idea to ask anyway at yamaha support

So yes Jeffie, you are right, he should ask yamaha for advice

Okay then Thanks for agreeing with me.

Hi all
I'm having exactly the same problem with the receiver just like the user who started this topic. Also i'm hearing some weird huming noise arround transformer, which breaks up and start. I read the http://http://www.diyforums.net/forums/index.php/ option=com_joomlaboard&Itemid=27&func=post& do=reply&replyto=44685&catid=7 and download a Yamaha RX-V795A.PDF service manual. Although I have v795 european model I check the basic diagnostic. From history report protecion funtions I PROTECTION is displayed for 2 seconds the before diagnosis
function menu will appear.
From service manual:

Appears when the current protection function is operating.
When power is turned on in an abnormal status, the power relay
will come on, protection will operate immediately, and power will
turn off.

So what are my options. Somebody mention the relay being dirty somehow.
And then soldering joints. myber some other suggestions. I'm gonna open the receiver tomorrow and see what I can do about it. Any more suggestions are much appreciated.