Left channel cutting out on sony DAS-R1. Advice?

[Duggeh]

So for a little while now my Sony DAS-R1 has had a problem with the left channel cutting out. It used to get better by itself after a minute or so, then it needed longer. Now I have the lid unscrewed all the time and give it a wee tap. While this cures the symptom it doesn't cure the disease and the wee tap is now turning into a prod, before I know it, I'll be using a frame hammer.

I'd like to fix this myself however I only just know which end of a soldering iron plugs into the mains and which end you use to burn your fingers touch against things to heat them up.

I've looked under the board and I cannot see any obviously broken connections. I am fairly certain that the problem is in the connection to "the big black cube". Simply because that's where I'd tap for the most sure fire results.

I throw myself upon the diagnostic wisdom of the great and the good here.

Photos resized to 1024x768. I'm also uploading the fullsize ones. I can photograph anything you like in detail if it helps.

[spritzer]

So if you tap the board and it gets better? If so then the relays probably are acting up and I'd start by replacing them. Those Omron's look to be no longer made but I'm sure they have a pin compatible replacement.

[Pars]

How are you with soldering? If it were me, I would probably resolder the connections to the big black cubes. Touch the iron to each connection and add a bit of solder. Try to make sure they are nice and shiny. See what that does...

[kevin gilmore]

next time it cuts out, tap the relay first. If you can be certain that it is the relay and can't

find a replacement, you can always short across the relay.

On second thought it does look like a bad solder joint on C334.

third thought bb204 is a grounding bar likely, so the relay may short

the audio to ground, so shorting across the relay would actually make

the sound disappear.

They sure don't build them like this anymore.

Going to try and find a schematic.

Edited March 25, 2012 by kevin gilmore

[Pars]

That relay supposedly crosses over to this NTE part:

http://www.mouser.com/ProductDetail/NTE/R40-11D2-12/?qs=e2FdSZXTP2ZSMFLmZpXHow%3d%3d

[kevin gilmore]

can't seem to find the schematic for free, but a few places are selling it for $5 to $10.

If you get desperate, buy it and post...

If its actually a bad solder joint to the big black cap, pulling up on the relay

end of it may temporarily cure the problem, in which case soldering just

that pin should do it.

Edited March 25, 2012 by kevin gilmore

[Duggeh]

Thank you so much for the input so far guys.

I don't think it is an issue with the relays (parts labelled OMRON) as a bit of work with forefinger and thumb confirms that tapping on those or anywhere else does nowt, while applying torque clockwise or anticlockwise to the large black capacitor (C334) brings back the music. This force might be moving the relay as well of course. I'm going to bring the DAC down to my desk and dig out my soldering iron. I hate moving the DAS-R1 because the mains lead is captive and getting it out means unbolting my drawers from the wall. Back soon.

Kevin if you link me to the schematic I'll buy it and post it. Least I can do.

[Duggeh]

Got the DAC down and open. Under magnification one of the joints on C334 does appear broken. This is the best picture I could manage. I'll resolder it and see if all is cured.

[Filburt]

Looks like it needs to be resoldered. If you are experienced at soldering can do it quickly, I'd reflow w/ a bit of new solder then wick it out, and then resolder. However, you can probably just reflow w/ a bit of solder and go from there.

[The Monkey]

The suspense is killing me! It would be awesome if the bad joint is the culprit.

[Duggeh]

I used a solder sucker to remove the old joint then soldered it again. It isn't perfect. But it isn't a mess.

Plugged it into the fiio e11, because a 20 kilogram DAC into a 20 gram amp is the done thing. Left channel is working fine and doesn't cut out if tapping or torque is deployed. So I venture to hope that it's fixed.

DAC Saved! Thanks all!

Edited March 25, 2012 by Duggeh

[Knuckledragger]

That was quick turnaround indeed.

[swt61]

Nice work!

Duggeh, now that you're an experienced DIYer, I'll send along a list of projects I'd like built.

Edited March 26, 2012 by swt61

[kevin gilmore]

This is what we do

[Duggeh]

Nice work!

Duggeh, now that you're an experienced DIYer, I'll send along a list of projects I'd like built.

I'll get started on that SRM-T2 for you just as soon as I figure out how the battery goes into this multimeter

[morphsci]

That was awesomely efficient.

[deepak]

Doug I shall inform HPA to add you to his PM list of KGSSHV builders

[n_maher]

Just think, at head-fi this thread would be 42 pages long with no solution.

Congrat Doug!

[The Monkey]

WIN

[Salt Peanuts]

Yay!

[HeadphoneAddict]

Doug I shall inform HPA to add you to his PM list of KGSSHV builders

Just don't get UPS involved.

[spritzer]

Long live simple fixes. If anybody wants the full service manual, drop me a line since I do have it.

[Duggeh]

I could have thrown in that one of the coax inputs doesn't work to see what might be done about that, but I only need one of them and have no plans to sell it so it seems moot.

Listening now. Sounds better than ever. Clearly I used magical Russ Andrews solder

[kevin gilmore]

courtesy the stax mafia

http://gilmore.chem....sr1_sm_sony.pdf

Edited March 26, 2012 by kevin gilmore

[spritzer]

I'm looking at the schematic for the digital inputs but I don't think I understand half of it.

Edit. I see Kevin got the service manual.

Edited March 26, 2012 by spritzer