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    HT-R590 No Sound

    Another Onkyo no-sound complaint, only a little late for warranty help

    My HT-R590 stopped outputting sound of any kind. Everything else seems to work (display on, HDMI video inputs/outputs to TV, AM/FM tune into correct stations). The TI chip on the HDMI board is wirebound, not BGA flip-chip. It is D808K013BPTP3, which appears to be in the list of TI chips from this link: https://cdn.badcaps-static.com/pdfs/...12b2bc512f.pdf
    Is this suspect (it's a rev.B chip, which seems to be part of the global issue)?

    Otherwise, any suggestions for debugging? I can hear multiple relays clicking when I power on the unit. I have measured the transformer primary and secondary voltages (it looks like 40 volts to the AMP board, I think nearly 100V to the power amplifiers on the large heat sink). I have the service manual and have been crawling through the schematics looking for anything interesting. The only sign of damage is a slight burn mark on the AMP board near the resistors for the +/-15V regulators, which is very near the undermounted R2A15218FP input selector chip. It just seems like the signal is not getting to the speakers (or maybe not even through the main amp, but I don't know how to tell). Any suggestions on where to probe next (I have good DMM and o-scope)?

    Thanks!
    Last edited by schenckb; 01-03-2021, 12:52 PM.

    #2
    Re: HT-R590 No Sound

    Adding some pictures, although I didn't take them when I had everything disassembled. The red circles/arrows point to the burn marks (the resistors, diodes, and caps in the area all measure fine when I had them de-soldered from the board).
    Attached Files

    Comment


      #3
      Re: HT-R590 No Sound

      Check out the subwoofer pre-out for signal. If I remember correctly, it's signal should come straight from the volume control/input selector IC ( the RA... one ).
      Just be sure to select a dsp mode which should use that output ( and to have the subwoofer activated in the amp's settings ).

      By the way, do you have the speaker icons on the display?
      Last edited by madan1; 01-03-2021, 04:15 PM.

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        #4
        Re: HT-R590 No Sound

        I don't recall ever seeing the speaker icons on this display (the manual doesn't show that as an option either). I actually looked for that when reading about similar issues with the TX units, but I think it's one less feature on these HT units.

        I checked the SW (subwoofer) PRE-OUT. I've got 0VAC regardless of which "music" mode output I'm in ("Direct" mode makes a relay toggle, I'm guessing that's as raw as it gets?). The sub is enabled in the menus. I plugged the sub in to make sure I wasn't getting any signal, and I also attached probes to the other end of the sub wire (fwiw, there is 20k resistance across the +/-).

        In the service manual, SW PRE-OUT comes from an op-amp (NJM4580), which is sourced from R2A chip, at least according to service manual (pic attached).


        Thanks!
        Attached Files

        Comment


          #5
          Re: HT-R590 No Sound

          I meant to add one more thing. I did check the 15V regulators again today, and both were pretty close (-15.18V, +14.89V). It's incredibly hard to get a probe to those pins with the unit assembled, and I can't really disassemble since most of the riser cards won't work if not plugged in AND attached to the chassis for the system ground. I can't think of any way to probe the underside of the amp board while powered, because it relies on this back plane ground.

          I'd really like to get closer to this R2A chip (Q4001) and measure the +/-7V zeners and caps near that voltage source (D4171/D4172). It'd also be nice to try to probe the outputs of the R2A (Q4001) either directly, or on the input to the DC decoupling cap most of them feed (it looks like 47uF, largely).

          Circling back shortly, I have been wondering about a bad earth ground in the design. As I've managed to get the system to shut itself off more than once after forgetting to secure some screws, I'd imagine that a bad ground would lead to far more than just missing sound outputs.

          Thanks for the continued help!
          Last edited by schenckb; 01-04-2021, 01:47 PM.

          Comment


            #6
            Re: HT-R590 No Sound

            Right, checked the user manual - no speaker icons.
            About the subwoofer signal - yes, makes sense other components to be involved since its signal is generated by the "smart part" ( my bad, I was thinking about the FL/R and zone pre-output signals ).

            So, check page 4 of the SM - this is the analog signal flow chart.
            To see if the R2A ic is doing its job to switch the input signals and send the analog audio for digital processing, probe pins 47 and 48 on q301 ( the small square IC on the hdmi board, close to the connectors ). On those pins you should see/hear the selected input signal ( a DSP mode should be on ).

            Once the signal is processed by the "smart part", it is converted back to analog by q351 and fed again to the R2A.
            Try probing that processed signal on the side board that connects the HDMI with the main board.
            On that board there are several NJM4580 ICs. Q401, pin 1 is front left, so check if there is anything there ( it should be something similar to the input audio/analog signal ).

            And finally, on q6001 ( a power amp IC ) pins 14 and 15 are the FL and FR inputs, where you should also be able to see the analog input signals.

            Since you have a scope, just feed a sine wave signal ( 100hz for instance ) and then probe the above points with it.


            p.s. About the ground - yes, that units need a good ground, which usually is provided by the backplate. I had a case where an onkyo unit was just clicking relays due to missing backplate.
            Last edited by madan1; 01-04-2021, 02:10 PM.

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              #7
              Re: HT-R590 No Sound

              Much appreciation for the continued help!

              I was able to probe those points. The LTAD and RTAD signals (pins 47 and 48 on Q301) both have probe points on the HDMI card, and I can see a signal that correlates to my FM tuner (I can switch to different inputs and see the signal go flat or change depending on what I have attached). I don't have a signal generator (only a scope), but I have enough information to know that those are working. The AC voltage is ~0.5VAC peak-to-peak, with a 3.3V DC offset, which seems reasonable for an unamplified signal (I really have no idea ). Further, the LTAD/RTAD solder points on the riser card (BCDG-0639) from connector P8002 show a signal and continuity to Q301 pins 47 and 48. So, I think that means R2A is working.

              Unfortunately, those are almost the ONLY test points (solder points) on any of the P8001/P8002/P8003 ports that seem to have a signal. The only other non-zero values are TU_SCL/TU_SDA/~TU_RST (which looks like I2C on my scope, as expected by naming convention), and the 3.3V line. OPTI1 is also at 3.3V. The SPRLF, SPRLCS, SPRLSB signals are all a flat 3.3V, as well as SEC1OFF. More interesting, AMUT and MICMUT are both 3.3V (and I think AMUT is the most interesting of those, given what I've seen in other comments).

              I have to run out for a few, but I intend to start tracing the AMUT down. Does that generally block the DSP output if active?
              Last edited by schenckb; 01-04-2021, 09:18 PM.

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                #8
                Re: HT-R590 No Sound

                You do not really need a signal generator - connect your phone/pc/laptop to any input and play one of those "1hr test signal" youtube videos. Believe me - much easier to work with.
                Check the downstream signal from the HDMI board. If you don't have access to q401, you should be able to reach the backside of connector P5502A on the bottom side of the side board.

                Comment


                  #9
                  Re: HT-R590 No Sound

                  Hi madan1,

                  There is no data signal (input or output) on Q401 (or any of the other 3 dual op-amp chips). I tried hooking up my PC through HDMI to play a 1KHz test signal, but quickly realized that must get resampled to a much higher digital frequency (and combined with video data - something around 75MHz). So I found a 1/8" audio jack-to-RCA Y connector, and played the test signal through the composite inputs. I was able to verify that the RTAD/LTAD are still passing the "raw" signal into the Q301 chip, but again, nothing out of the Q351 or at the Q40x op-amps.

                  I did verify +/-15V on the op-amp pins 4/8, so they appear to be getting power, just no signal.

                  I did find a couple of reset and mute signals in the design. One in particular (DACRST) seems to be "1" (that is, the inverted DACRST that does into the DAC is 0V). Is it worth starting to trace some of these RESETs? Or is there a way to narrow this down to the DSP itself?

                  Thanks for all the help!

                  Comment


                    #10
                    Re: HT-R590 No Sound

                    I'll not be able to help you much with the digital part - my experience ends with determining if the the digital ICs get their proper power supply.
                    By the way, check if the vol/input selector IC is switching the inputs - this will tell you if the main control unit is communicating with it ( like feed analog audio test signal to CD, then AUX, etc. and see if the IC is switching them ).
                    Also check the signal flow chart from the service manual - I think after the ADC, the signal goes through the DSP IC, then to the DAC and back to the R2A.
                    Basically you have 3 ICs which might not work properly or are missing power supply ( ADC, DSP, DAC + ram chip(s) and a CPU which seems to be working at least to a certain extent ) .
                    See if the service/debug mode doesn't have options to diagnose the proper communication between the main control unit ( CPU ), the DSP and the other smart parts ( I'm pretty sure there is such an option ).
                    If the unit has auto speaker setup, then you can use it to generate test signal through all outputs ( which you should be able to probe on the op-ams on the side board ). Such test signal option should also be present in the service/debug mode.
                    Last edited by madan1; 01-09-2021, 03:20 PM.

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                      #11
                      Re: HT-R590 No Sound

                      Thanks - I will poke around some more.
                      I reread through this, and have been spending some time on YouTube. It seems like this unit has some Debug reporting capabilities, but the Service Manual doesn't describe any of the procedure or the field decodes. I do see that the service manual for HT-R591 has a lot more info, but I am unsure if this would apply to HT-R590. Does anyone have more information on how to use the debug modes? One point; the DSP shows all ???, so that's something.

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