OK no laughter: Onkyo TX-SV515PRO a/v receiver with issues

mhardy6647

Lunatic Member
One big issue: dead as a doornail.

On the scrap metal pile at the dump last week. In the rain. But cosmetically like new. Heavy mortar forker, too. Black, but not plastic. Crap? Who can tell?

Brought home (I am such a sucker); dried out. Tested. Nada. Popped the top. Found three fuses, all good. This is modern enough that it has no "hard" power switch at all. I assume the "PRO" moniker refers to Dolby Pro Logic.

Onkyo has the owners manual online (which is nice of them): http://63.148.251.135/redirect_service.cfm?type=own_manuals&file=tx_sv515pro.pdf

The only reason that I am posting this is that hope springs eternal. Perhaps one of you sees the thread title and says, "oh, yeah... there's that one resistor on the P/S board that fries. Gets 'em every time." As opposed to saying "nice black doorstop you've got there, pal". Or maybe "there's 15 more fuses under one of those PC boards, lunkhead!"

Fortunately the dump has a generous return policy... but I figured I might as well ask before I take advantage of it.

Thanks as always!
 
Not going to pursue this one... I am planning to drop it on the freebie table at NEARC Saturday.

It's beefy, though.
 

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It it had been just a blown fuse, hardy would be getting the last laugh. I applaud the effort!
 
ha! seems like it's a common problem. if you google the model number it comes up with countless 'won't turn on!' links.
http://www.fixya.com/support/t1224676-onkyo_tx_sv515pro_will_not_turn

obviously some design or build fault, might be the easy secret for Onkyo experts or might be a "that's when you throw them away"...

I'd test the transformer, see if it's putting out juice. Then I'd scope out that little power supply board and see if there's a relay that's not kicking over or getting the right switch signal from the front panel button.

If those simple 'getting power' issues don't reveal any easy solver problems I'd then make the 'toss or give away' decision as to whether to go forward.
 
I suspect there's a "fuse" in the power transformer that's open, but that's just a guess (not substantiated by any measurements of said PT). The PT is a big, beefy hunk of iron and copper shielded as you may be able to see. The whole Rx is quite substantial -- it's really a shame that it's kaput. Onkyo never really stopped making decent stuff.

EDIT: yes I saw that fixya link, but it wasn't terribly helpful (other than to hear that there are other dead ones out there, which somehow didn't surprise me too much!)
 
Brought home (I am such a sucker); dried out. Tested. Nada. Popped the top. Found three fuses, all good. This is modern enough that it has no "hard" power switch at all. I assume the "PRO" moniker refers to Dolby Pro Logic.

You said it was an Audio Visual Receiver and no hard power switch. That combination screams remote control power on off function and a phantom power circuit to keep the remote control's receiver alive in the "off" condition. I would suspect that circuitry. If you can isolate the primary on the transformer you might be able to bring the rest of the unit up by bypassing all the remote stuff and bringing power to the transformer.

No - sorry - I have no idea how to troubleshoot the remote's receiver.

Just a thought.

Shelly_D
 
Yep, in that charred area, dollars to donuts says it's the driver stage, and that ojne or more components are GONERS...
 
Dang you are right, Celt. I didn't notice the discoloration IRL, but I took some more photos (with a good camera this time) and saw it... went back down and looked at the beast and it is visible (although harder to see in situ).

You said it was an Audio Visual Receiver and no hard power switch. That combination screams remote control power on off function and a phantom power circuit to keep the remote control's receiver alive in the "off" condition. I would suspect that circuitry. If you can isolate the primary on the transformer you might be able to bring the rest of the unit up by bypassing all the remote stuff and bringing power to the transformer.

No - sorry - I have no idea how to troubleshoot the remote's receiver.

Just a thought.

Shelly_D

I've walked that road with a Kenwood preamp once -- certainly possible in this case, but I sort of doubt it.
 

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I know I worked on some of these when they were new. Pretty decent receivers actually. The top end of the line were very nice. Unfortunately there is no bottom panel, so to repair it the entire board has to come out and all the sub boards. Yuck. I think that is a driver stage that is smoked, but the reason it won't turn on is likely in the 5V standby supply as stated earlier. I have never seen an Onkyo transformer open up, so I doubt the big one is gone.
 
Had an Onkyo R1(?) reciever given to me because it didn't work. There was a ground screw loose. Tightened it to restore contact, and voila!
Don't know how I figured it out since I'm not skilled that way...
 
Had an Onkyo R1(?) reciever given to me because it didn't work. There was a ground screw loose. Tightened it to restore contact, and voila!
Don't know how I figured it out since I'm not skilled that way...

Now you are!:thmbsp:
 
I second the charred PCB. These generations of onkyos had extremely hot regulated supplies. There are fuseable resistors on that area that were underrated for the job watt wise.
They get so hot they will literally burn open foil traces. the early signs of failure are random turning on and off caused by intermittent 5 and 12v supplies to the syscon IC.

Pull off the bottom and check that blackened area. Ohm out the foil traces with a DMM to make sure none are broken or any fuseable resistors are open. At the very least they have probably come loose.
 
The plot thickened a little on this.
I decided NOT to take it to NEARC today and leave it on the freebie pile.
This afternoon I plugged it in again... this time, an orange LED under the standby/power switch is lit (it seems to mean "standby") and another orange LED by the "MR off" button (MR = multiroom remote, I think) is lit. When the power switch is pushed, a relay clicks, the orange LED by the power switch goes off, but the display doesn't light up. I tried "turning off" the MR off (whereupon its LED extinguishes), but that has no effect on the aforementioned symptoms. I swear I didn't get the LEDs or the relay click the last two times I tried this thing.

I am going to actually look at the manual a little now (Onkyo had it on their D/L page). Any further thoughts are always welcome, though.
 
heh. the plot thickens. I took a Zenith universal remote control I found at the dump last week :) dug up programming instructions (and a code list) off teh interwebs, and tried the "Onkyo receiver" code. The penultimate (next to last, that is) code worked; the receiver responds to the remote; turns "on" and "off" (i.e, standby light goes "off" and "on" respectively). Now here's the amusing part. I pushed the volume up and down buttons on the remote... and the motorized volume control on the Rx obediently dialed "up" and "down". The indicator LED in the volume control's knob is not lit, and the display is resolutely dark, but the thing is obviously conscious :)

At this point I hooked speakers to it and tried "blindly" selecting some sources from the front panel. No life at the outputs.

The fried VR stages certainly seems plausible... but this kind of equipment's beyond my meager troubleshooting skills.

Still it's tantalizing...
 
inspect the solder joints and board traces in the reg. supply. A bit of soldering may be all it needs.
 
urkey-derky... I think that means popping the board(s) loose as someone (maybe even you!) mentioned there was no access from below (although I do have tinners' snips...).

I did 'squeeze' all the wire wraps with a pair of pliers in one of the previous sorties.
 
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