Getting an Onkyo TX-SR875 repaired

ciotog

Didn't want to post in the Dublin hi-fi repair zombie thread, but it's timely. I'm weighing up the potential cost of getting my Onkyo TX-SR875 repaired versus going to a newer budget AV receiver (my requirements are modest as an apartment dweller). Would appreciate suggestions for repairs in the Dublin area.

A bit more about the issue (in case anyone's particularly interested): I'm not getting any output from the front right speaker output. A visual inspection doesn't reveal any blown capacitors or anything user serviceable. My skills with a multimeter and electronics aren't up to exploratory testing so would need to get someone to find the fault and repair.

akaSol

ciotog wrote: »

Didn't want to post in the Dublin hi-fi repair zombie thread, but it's timely. I'm weighing up the potential cost of getting my Onkyo TX-SR875 repaired versus going to a newer budget AV receiver (my requirements are modest as an apartment dweller). Would appreciate suggestions for repairs in the Dublin area.

A bit more about the issue (in case anyone's particularly interested): I'm not getting any output from the front right speaker output. A visual inspection doesn't reveal any blown capacitors or anything user serviceable. My skills with a multimeter and electronics aren't up to exploratory testing so would need to get someone to find the fault and repair.

Best case is something small, worst case scenario is a whole board. Don't forget the 875 is a big amp and not exactly cheap when first purchased so speculating €200/300 as a repair is well within what I would be comfortable with. Also any new amp around the €300 mark is going to sound like a blue tooth speaker by comparison.
Try contacting onkyo directly, they have a reasonable customer service, failing that Hifi hospital or any other Hifi store (check if they sell onkyo so it's easier to go back )

ZENER

At the rear of the amplifier there is a section labeled "Pre Out"

If you have any sort of other amplifier, with a line or AUX input, try connecting the FRONT section to it.

The purpose of this is to determine if it's the processor that's faulty or the power amplifiers are at fault. If you find both channels from this output are working then we may be able to trace the fault for you. If the right channel still doesn't work at this output it could mean the fault is further back.

Ken

ciotog

akaSol wrote: »

Best case is something small, worst case scenario is a whole board. Don't forget the 875 is a big amp and not exactly cheap when first purchased so speculating €200/300 as a repair is well within what I would be comfortable with. Also any new amp around the €300 mark is going to sound like a blue tooth speaker by comparison.
Try contacting onkyo directly, they have a reasonable customer service, failing that Hifi hospital or any other Hifi store (check if they sell onkyo so it's easier to go back )

All good points - would love a local repair store as it's a beast to pack and ship I only have two floor standers connected which is why I was considering just scaling back. Circumstances have changed in the ~7 years I've had it such that I'm not going to be looking to drive a big sound / setup anytime soon.

ciotog

ZENER wrote: »

At the rear of the amplifier there is a section labeled "Pre Out"

If you have any sort of other amplifier, with a line or AUX input, try connecting the FRONT section to it.

The purpose of this is to determine if it's the processor that's faulty or the power amplifiers are at fault. If you find both channels from this output are working then we may be able to trace the fault for you. If the right channel still doesn't work at this output it could mean the fault is further back.

Ken

Thanks Ken, I'll have a look into what I can do here. Appreciate the help very much.

ZENER

ciotog wrote:

Thanks Ken, I'll have a look into what I can do here. Appreciate the help very much.

If you're only using 2 speakers then use the Zone 1&2 outputs! Read the manual to see what they do. They are configurable as outputs for bi-amping so will replicate the main L&R front outputs. I can link to the user manual if you want.

Ken

ciotog

ZENER wrote: »

If you're only using 2 speakers then use the Zone 1&2 outputs! Read the manual to see what they do. They are configurable as outputs for bi-amping so will replicate the main L&R front outputs. I can link to the user manual if you want.

Ken

That had occurred to me but those zone outputs don't support digital input sources - which at the moment describes everything connected (they have that information tucked away under Selecting an Input Source for Zones)!

Edit: Just for interest (possible diagnostic value), I connected the speakers to the Zone 2 L + R outputs with headphone jack output to the CD in and got the same issue with the output from just one speaker.

ZENER

Read page 22 & 23 of the user manual on Bi-Amping but connect the speakers to the ZONE * outputs only. The circuit diagrams show that the SR and SL outputs are connected to the ZONE outputs via relays when this mode is selected. It might help to discern which area is the problem.

From your last post it sounds like the fault is back in the processing stage but hopefully this will prove it.

Ken

ciotog

ZENER wrote: »

Read page 22 & 23 of the user manual on Bi-Amping but connect the speakers to the ZONE * outputs only. The circuit diagrams show that the SR and SL outputs are connected to the ZONE outputs via relays when this mode is selected. It might help to discern which area is the problem.

From your last post it sounds like the fault is back in the processing stage but hopefully this will prove it.

Ken

Sorry, for just coming back to you now - I haven't had a chance to try this yet. I'm not sure if I can do this test; the manual notes that bi-amping should only be done with speakers where their impedance is >= 8 ohms. What I have are 6 (Monitor Audio BR5s) so I'll need to check.

ZENER

I doubt it'll be an issue and besides it's just a test so not a long term solution. Unless you intend running at very high volumes continuously I also wouldn't be too worried.

The test I was more interested in and which will reveal more is the PRE OUT stage into another amplifier, could you try this first ? If there is no RIGHT channel signal here then the problem is further back in the processing stages/control stages of the amp.

Ken

ciotog

So, it took quite awhile to organise this test but I finally got to try the PRE OUT.
Fed audio in via TAPE and connected an amp to FRONT on the PRE OUT BLOCK (I also connected it to Zone 3 for curiosity sake). Result is that I get left and right output with the speakers (for both these variants).

Speculation: Could well be way off (high on sugar) but could it be a case that I'm looking at an issue with what's identified as NAAMP-9062 (U17) on SCHEMATIC DIAGRAM-4 (SD-4), POWER AMPLIFIER SECTION-2 in http://oli189.free.fr/Service.Manual_TX-SR875.pdf ?