Receiver Onkyo HT-R570 no sound .

[petehall347]

Re: Receiver Onkyo HT-R570 no sound .

is tape switch set to source ?

[RogerioBarbosa]

Re: Receiver Onkyo HT-R570 no sound .

Yes, there is a MUTE button on the remote, but it is not changing this line that is always triggering the transistor Q5600 at part5: G5. I'm confused because there is a line called MUTE, which I suppose would be the MUTE line.

[petehall347]

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.

i would cut the base and see what happens . or i might separate pre from main then inject signal to main . well only if main amp is testing ok current and offset .

[R_J]

Re: Receiver Onkyo HT-R570 no sound .

Check the voltage on POFF (page21) These amps do mute while powering on or off, that might have something to do with it?
Just to be sure you can check the amp offset voltage on JL6600B, all pins should be close to 0 volts

[RogerioBarbosa]

Re: Receiver Onkyo HT-R570 no sound .

I opened the AMUT line and the V at the base of the Q5600 transistor changed from 2.5V to -15V, so the transistor no longer landed the signal, but the sound did not appear.

[R_J]

Re: Receiver Onkyo HT-R570 no sound .

This AMUTE is likely a control line that the microprocessor uses to mute the audio when sources are switched etc. so you don't get a pop in the audio when you switch sources. That would be my guess since I don't know the microprocessor's program code.

[RogerioBarbosa]

Re: Receiver Onkyo HT-R570 no sound .

Ok, tank you about AMUTE. I injected audio into the CD input and placed the oscilloscope in the Q5600 collector and got no signal.I know Q5600 is not driving because his base is with -15V

[R_J]

Re: Receiver Onkyo HT-R570 no sound .

The conrtrol line must be open and the R6681 is the pullup to the -15 volt line, so AMUT must need to be taken low to un-mute the amp, or in this case taken to +5volts
Check the voltage on Q752, and Q751, then check Q703 regulator, It seems to supply Q752 via D702 and R711(47Ω)
I think Q793 is a 5.6 volt regulator, it is supplied by the +10VS (from the standby circuit)

[RogerioBarbosa]

Re: Receiver Onkyo HT-R570 no sound .

Hi, I am back, and I did not resolve the problem yet. I needed stop thinking in the problem because I did not have much time since the last time that I decided to fix de receiver. I will start thinking in the problem again. and would apreciate any sugestions. Thanks

[Stroog]

Re: Receiver Onkyo HT-R570 no sound .

Hello. I know this topic is a little too old but I have this same receiver and i think it has a problem in this ci (R2A1521RFP). It receives a analogic audio input from dvd or others inputs but nothing comes out. VCC is ok. I found it on aliexpress but before trying to replace it i'm trying to figure out if it is muted or not. It receives a signal from another CI (T5CN5, microcontroler) in pin 51. MUTE. Its a high level 3.3V signal. It becomes high when the receiver is turned on and stayed high all the time. I cant find the datasheet in inet to discover if its active in high ou low state. Anyone here knows anything about this ci to claryfing this form me pls. I dont want to expend 10 bucks and a lot of work for nothing. Thanks in advance.

[Stroog]

Re: Receiver Onkyo HT-R570 no sound .

Sorry Im seeing it now. My receiver is a denon. AVR-391. But its the same IC so i think its all the same. Thanks.

[nodols]

Re: Receiver Onkyo HT-R570 no sound .

Sorry Im seeing it now. My receiver is a denon. AVR-391. But its the same IC so i think its all the same. Thanks.

Did you try change the IC?

I'm on the same boat, it seems this IC is in many brands. I saw this on an Arcam, Onkyo, and now you have it in Denon. So I'm guessing this is pretty common.

I believe I've read it from somewhere that logic high on pin51 is muting this IC. In your case it's probably the processor is sending a mute signal to this IC, and might be an issue somewhere and not this IC.

[madan1]

Re: Receiver Onkyo HT-R570 no sound .

If you have an onkyo, denon, pioneer and probably more from that era ( 2005-2015 ) first check if your model uses the defective texas instruments DSP chips.