Receiver Onkyo HT-R570 no sound .

[RogerioBarbosa]

My receiver stopped playing any sound suddenly. I tried all the entrees and nothing.
I decided to measure +/- 7V which are responsible for the operation of the R2A15218FP chip, and the + 7V was only +6V. I measured the + 15V and it was only + 14V. The line - 7V, was ok. After many measurements and exchange of some caps, I realized that when I disconnect the turner pack, the + 7V returns to normal, but the -7V drops to -6V. From the tests I did, it does not seem to be a source problem. Any idea? Thank you very much, because this receiver is really hard to repair.

[budm]

Re: Receiver Onkyo HT-R570 no sound .

Do you hear speaker protection relays click on a few seconds later after turning on the receiver?
Do you get audio at the RCA Tape out jacks on the rear panel of the receiver?

[RogerioBarbosa]

Re: Receiver Onkyo HT-R570 no sound .

Yes I hear speaker protection relays click on a few seconds later.
No audio at the RCA Tape out jacks on the rear panel of the receiver.

[RogerioBarbosa]

Re: Receiver Onkyo HT-R570 no sound .

I changed the Tuner Pack and the problem remained the same. It may be some circuit that may be draining more current than it should. I measured the current that the Turner Pack is consuming and it was 60mA, less than specified in the service manual (100mA).

[RogerioBarbosa]

Re: Receiver Onkyo HT-R570 no sound .

Any help?

[R_J]

Re: Receiver Onkyo HT-R570 no sound .

Have you tried doing a master reset on the receiver

[RogerioBarbosa]

Re: Receiver Onkyo HT-R570 no sound .

Thank you, Yes I did.
It seems to be really an electronic problem. I made a table with the V + and V- with the Turner pack and without the Turner pack.
--------------------------------------------------------------------------------------------
Should be +22V / -B / +15V / +7V / - 7V
With Turner pack +20.2V / -31.6V / +8.9V / +1V / -12.7V
Without Turner pack +27,1V / -26V / +15,5V / +7,5V / -6,1V
-------------------------------------------------------------------------------------------
Any suggestion?
Thank´s a lot.

[RogerioBarbosa]

Re: Receiver Onkyo HT-R570 no sound .

I forgot -15 V, With turner pack -> -20,5V
Without turner pack -> -13,8V

[RogerioBarbosa]

Re: Receiver Onkyo HT-R570 no sound .

+- 15V power supply and +- 7V power supply and service manual.

[R_J]

Re: Receiver Onkyo HT-R570 no sound .

The tuner should not effect the NO AUDIO condition. The amp should operate without it connected to P101A and the tuner operates from 9 volts which is supplied via Q111 from the +12 [+15v] volt supply
I can't see how connecting the tuner pack would have that much effect on the voltages, unless it's vcc is shorted.

If the tuner +9VTU is shorted, that would kill the 9 volts on Q111 and load the +15 volts causing it to drop. or Q111 could be shorted?

[RogerioBarbosa]

Re: Receiver Onkyo HT-R570 no sound .

tuner is ok I exchanged the original for another and the problem persisted. I'll check the transistor. Thank you.

[RogerioBarbosa]

Re: Receiver Onkyo HT-R570 no sound .

what I do not understand how the tuner can affect the -15V power suply, if its power suply is only + 9V, derived from the + 15V .

[R_J]

Re: Receiver Onkyo HT-R570 no sound .

It almosts looks like an open ground somewhere. If you are working on the amp with it disassembled, it could be a ground path is missing, this happens a lot with these amps, as an example they sometimes rely on the rear plate for completing the ground between some of the boards.

[budm]

Re: Receiver Onkyo HT-R570 no sound .

[QUOTE=R_J;906254]It almosts looks like an open ground somewhere. If you are working on the amp with it disassembled, it could be a ground path is missing, this happens a lot with these amps, as an example they sometimes rely on the rear plate for completing the ground between some of the boards.[/QUOTE]

+1

That may explain why you have that strange reading below in your post 8:
"I forgot -15 V, With turner pack -> -20,5V
Without turner pack -> -13,8V"

Most of these rely on metal chassis to complete the circuit ground, that is why it is important to make sure all the board mounting screws are tight.

[RogerioBarbosa]

Re: Receiver Onkyo HT-R570 no sound .

Thank you very much. You are completly right! When I put the 37 screws back into the back cover, all +/- V returned to normal. I was putting some screws back in place to measure. But now the original problem persists: No sound. It all started when I decided to measure the +/- 7V, because for me the problem is in the Q5501 IC that seems not to be working. I do not know how to test it, I started by testing the +/- 7V, and measured + 6V instead of + 7V. I thought this is the problem because this IC works with values between +6.5V and 7.5V, but I was wrong about +7V because now with the back screws I have +/- 7V back on the IC. I do not know if this IC could burn. But the problem appeared after the device had been disconnected for a year. A year before when I turned it off, it was working perfectly, when I turned it on a year later it did not have any sound. I thought: some cap must have dried up. Now I do not know what to do, because changing that IC is not so simple. and I'm not sure if the problem is really in Q5501. Any suggestion?

[RogerioBarbosa]

Re: Receiver Onkyo HT-R570 no sound .

With +/- 7V ok, I've injected audio into the CD IN, CAB / SAT IN jacks, and got audio out on TV / TAPE OUT, This suggests that the Q5501 IC is ok. The inputs are being switched by IC. So why do not I have audio output? I went back into the darkness. I tried to find datasheet of R2A15218FP, but I could not get the pdf. Any suggestion? Thank you.

[R_J]

Re: Receiver Onkyo HT-R570 no sound .

Does this receiver have the speaker test/setup feature? Page 25 of owners manual,
Use q/w to select “Audyssey Quick Start” or “Audyssey 2EQ Full Calibration"
If it does this should produce test tones to check the outputs.
It's hard to trace audio signals without a scope.

[RogerioBarbosa]

Re: Receiver Onkyo HT-R570 no sound .

Thank you,Yes, it has speaker test/setup feature, but no sound during the test.
I think the receiver is muting, because there is a protection circuit that doesn't allow the sound to reach the power amplifiers in case of something goes wrong. I measured the *V at the base of one of these transistors, and it is positive(2,5V), indicating that it is conducting and ground the power amplifier imput signal , after the pre-anplifier.(Q5600 at part5:G5).The problem now is: Why this V at the transistor base? There is a signal called AMUT, I don´t know exatly it means, but could be this signal that is doing the transistor ground the signal that goes to the power amplifiers.

[RogerioBarbosa]

Re: Receiver Onkyo HT-R570 no sound .

This signal (AMUT) is controlled by a signal from the Q701 IC called AMUT_COM (I also don't know what this signal means). But I suppose it should act in case the something goes wrong. I don´t know what yet. Any suggestion? Thank you very much.

[R_J]

Re: Receiver Onkyo HT-R570 no sound .

Is there a MUTE button on the remote? and does it change this line? This looks like it is only for muting the audio and not for any protection in case of a fault.
AMUT_CON = audio mute control, It is just the control line for the mute circut.