Denon AVR-1912 E2/EA

[Michael Studio1]

At this point I might change tactics from trying to pinpoint the exact signal path to just a general evaluation of what works and what doesn't.
Perhaps you've done this already but I'm not aware of the synopsis.

Try feeding line level audio into each input jack and with the proper input selected, see what works.
Example: Plug your CD player into the CD jack, select CD on the input selector, put volume to moderate level and see if anything comes from Left or Right speaker. If not, try the pre-out jack and test with your amplified audio sniffer. Also try the headphones jack.
Move on to the other inputs and see if any of those are working. Try experiment with things on the panel and see if anything comes to life. Try to initially avoid digitally decoded modes such as DTS, AC3, Prologic, Atmos ..etc.
Instead try a sound mode that will simply pass the signal through like "stereo"

Hello John - many thanks for this procedure. I have't tried feeding any Inpits except the Default (VAUX] and CD IN (by IN SELECT) - both of which take Line Level signal. So I am grateful for your studied answer which I shall follow during the course of the day - and post any result! Michael Studio1 UK 06:11BST 12-05-2018

 

[Michael Studio1]

I am looking at the Service Manual and have set 'Find' (Ctrl+F) for 'PRE OUT' and it guides me to a Phono socket on the back panel labelled 'SUBWOOFER' and 'PRE-OUT'. It also guides me to Page169 which is all to do with that 'other' version of the IC801.(on page114) 'FIND' also refers to: CN/CP401 and the 7CH_AMP 1/2 (page106/A4) it also refers to: 1 Phono socket (SUB WOOFER) and to 4 Phono sockets of JK102 (page114/O7-9) The thing here is: how are these OUTPUT sockets used? with my Amp.Probe? I'll try it and find out! Michael Studio1 UK 15:33BST 12-05-2018.

 

[Michael Studio1]

OK. Later. I have injected tones L & R into all 5 Analog INPUTS, Selected each one with the INPUT SELECT knob and, using the Analog AMP Probe at C799 and C831 (these being the last accessible analog points to probe, checked that all 5 can be heard Pre-Digital. I must therefore and logically check that every IC is receiving the required Power - down the Route from IC29 (the ADC) to the 7CH input connector CN401 (page114/O3-4). We know that IC801 is functioning as the 2 tones have already been through it from pins 83/84 to pins 54/55 en route to IC29 - the AD converter. Therefore it only requires the testing of the working Voltages of the IC's through to the 7CH_AMP at CP401/CN401. where we have established the tones are not arriving. Michael Studio1 UK 16:51BST 12-05-2018

 

[Tha fios agaibh]

So you're saying nothing work other than the signal you trace to the point before cn401?

In other words, you've hooked up speakers and do not get any kind of sound through the amplifier? Radio has no output? You've plugged in headphones and there's no sound?

 

[Michael Studio1]

So you're saying nothing work other than the signal you trace to the point before cn401?

In other words, you've hooked up speakers and do not get any kind of sound through the amplifier? Radio has no output? You've plugged in headphones and there's no sound?

That is so, John. Zilch. But the tones from any of the Audio Inputs are getting as far as the AD converter - both Left and Right. I am yet to test the Supply Voltages at the IC's in the Digital area. Michael Studio1 UK 07:52BST 13-05-2018

 

[Michael Studio1]

Actually, John, you'll notice that the VAUX signal goes through that IC801 twice. Once as Analog and once as Digital. The last point it can be heard is at pins 1 & 2 of IC40 as ADINR and ADINL. (page 126/B5) It doesn't get as far as CN401 page106/A4-5. Just off to Brighton, Sussex -on-Sea for a French Breakfast at the Marina. Michael Studio1 UK 10:00BST 13-05-2018

 

[Michael Studio1]

I have spent a lotta time poring over the Cct.Diags. of this AVR-1912E2/EA and have made copious notes (to myself!) in order to follow the Digital and Power paths relating to the VAUXL and VAUXR Signal Tones Input - and where they go. First I have checked out the +8V and -8V - and the +5V. All OK. Now I am going to probe the Digital route - if only to see that my 'DS201 PRO digital storage oscilloscope' can do so meaningfully. Michael Studio1 UK 09:14BST 14-05-2018

 

[Tha fios agaibh]

I have spent a lotta time poring over the Cct.Diags. of this AVR-1912E2/EA and have made copious notes (to myself!) in order to follow the Digital and Power paths relating to the VAUXL and VAUXR Signal Tones Input - and where they go. First I have checked out the +8V and -8V - and the +5V. All OK. Now I am going to probe the Digital route - if only to see that my 'DS201 PRO digital storage oscilloscope' can do so meaningfully. Michael Studio1 UK 09:14BST 14-05-2018

It looks like after it leaves IC30 it arrives at IC21 on pin 24 then exits on pin 21.
Wish I was of more help to you but digital is not my forte.
You should read a slight voltage on the digital side to prove its not dead but other than that I can't say. Yes, your scope should give an indication if digital stream is alive. Give it a screen shot and post a picture of the wave and hopefully someone can help decipher it.
If you can trace where DataDir1 from pin 21 leads that might be helpful.
I even had the thought of using an inexpensive D/A converter (about £10)
to probe the digital signal but I'm not sure if that's feasible.
The best scenario would be to find a point where it changes back to analog.

 

[Michael Studio1]

It looks like after it leaves IC30 it arrives at IC21 on pin 24 then exits on pin 21.
Wish I was of more help to you but digital is not my forte.
You should read a slight voltage on the digital side to prove its not dead but other than that I can't say. Yes, your scope should give an indication if digital stream is alive. Give it a screen shot and post a picture of the wave and hopefully someone can help decipher it.
If you can trace where DataDir1 from pin 21 leads that might be helpful.
I even had the thought of using an inexpensive D/A converter (about £10)
to probe the digital signal but I'm not sure if that's feasible.
The best scenario would be to find a point where it changes back to analog.

Hello John - from a sun-bathed Sussex-by-the-Sea! Thanks for your thoughts. Useful and pointed as ever. There is a reasoning behind these 'Acronyms' - like your suggested DataDir1. These letters and numbers are always enclosed in directional 'boxes': [DATADIR1]> (I can't replicate this properly, so look at: pin21 of IC21 (page 124/D5) Note that IC21 is also named: DIR1 this 'trace' (for want of a better term) goes to IC22 pin44 and comes out at pin34 as <[DSP1INF/FR] and (believe it or not) lands up at p124/G10 in the first 'cluster' of connections enclosed together and routed: TO DSP Here my notes tell me is arrives on Page125/D1 and goesto that enormous 176pin U8 (ADSP21487KSWZ-383018) - for the AVR1912 - at pins 100&103 - leaving from pin86 as [DATAF]> emerging briefly at Page124/H10 before leaving from Page124/K10 to Page126/F1 as [DATAF]> going to IC29 pin14. This AK4358VQ must be a DA converter for in the Parts List (page189) it is called: IC ANALOG, the Output of which is at 4 pins with pin1 = LOUT1-, pin2 = LOUT1+, pin47 = ROUT1-, pin48 = ROUT1+. These two pairs are now routed to Amp. IC28A [FL] and IC28B [FR] and emerge as [DAFL]> and [DAFR]> still on page126/N3-4. Now off to page129/E3-5 (DIGITAL CNT) they become <[ADINL] and <[ADINR] at CN2 pin32 and pin30. CN2 is connected to CP11 on page112/J-L4 (FRONT CONNECTOR) ADINR (pin30) ADINL (pin32) on this CNT_B'D they emerge at CP115 pin15 A/D-R and pin17 A/D-L. Off now to page114/F-G1 pin15 A/D_R and pin17 A/D_L arriving at IC801 pin55 A/D_R and pin54 A/D_L. Because of the way it leaves this IC801 it is confusing that the DA Conversion should have already happened, for here they emerge at pin21 (FLOUT) and pin23 (FROUT) on their way to the 7CH amp at CN401 pin1 (FL) and pin 9 (FR). As the old song goes "And the music goes round - round & round, & round - and it comes out > HERE. Trouble is, it doesn't. There's no L&R Signal Tones at IC29 pins1&2 or pins47&48 and none at CN401 pins 1 and 9. My DS201 PRO Oscilloscope is Analog and will not measure Digital waveforms. So I have the wrong Oscilloscope for this test and need advice on the subject - which I shall post on Electronicspoint. Michael Studio1 UK 12:44BST 15-05-2018

 

[Michael Studio1]

John - I forgot to mention - a-propos your suggestion of a D/A Converter - Why I didn't think of this option is beyond me - but we have these in the Studio - so thanks I'll root one out and stick a probe on the I/P, touch a few select connections in the AVR and see what comes out! Good thinking!! Michael 12:51BST

 

[Tha fios agaibh]

From your description it sounds like you're getting to know this thing like the back of your hand.
A few thoughts; Originally the Right channel worked but the Left cut out. Correct?
I wonder why we don't even have the right channel now.
Are all the settings the same?
Is your Source set to Analog, Surround mode set to Direct, and the Zone set correctly for the speakers?
If you look at the block diagram on p33 the only thing between an analog input and the analog L&R Spk output is the switching done via IC801. Remind me again why we are chasing down the digital path when analog should routed through IC801on to the amp.

We should make sure all the settings (software) are right to pass the signal before jumping through hoops.

Might want to step-up the search for the remote and (again) get a monitor set-up so you can read the on-screen menus.

 

[Michael Studio1]

From your description it sounds like you're getting to know this thing like the back of your hand.
A few thoughts; Originally the Right channel worked but the Left cut out. Correct?
I wonder why we don't even have the right channel now.
Are all the settings the same?
Is your Source set to Analog, Surround mode set to Direct, and the Zone set correctly for the speakers?
If you look at the block diagram on p33 the only thing between an analog input and the analog L&R Spk output is the switching done via IC801. Remind me again why we are chasing down the digital path when analog should routed through IC801on to the amp.

We should make sure all the settings (software) are right to pass the signal before jumping through hoops.

Might want to step-up the search for the remote and (again) get a monitor set-up so you can read the on-screen menus.

Thanks, John. The loss of both L&R Channels occurred subsequent to the 'frying' of those 0.47Ω resistors and the Darlington Pair Q464 and Q470 in the SBL Channel. Remember? These have now been replaced - the Darlingtons came as a pair On-Line - very convenient. Because the L & R Signal tones from AUXL and AUXR actually get to the ADC IC30 (page 126/B6) at pins 1&2 - and leaving from pin9 as [DATAAD] but that's where I can no longer trace - so I'm in the dark as to whether IC30 is working or not - and likewise the following IC's through which the Digital Signal passes. This is why I am looking for an Oscilloscope which can read Digital Signals. It could be that the one I have can do so (a DSO201pro) and have asked the Chinese manufacturers for assistance and they have replied:
"If the signal is 5000-700, DS201pro can be measured,adjust the voltage position and time base.
------------------------------------------------------------------
发件人：Michael Gamble <[email protected]>
发送时间：2018年5月15日(星期二) 20:05"

Sorry about the beautiful Chinese hieroglyphs but I wonder whether that first number they show shouldn't be 500 - for that is what I sent them: 500L and 700R. In which case I have to 'adjust the voltage position and time base.' - or rather, I must find out how to do this! Michael Studio1 UK 13:15BST 16-05-2018

 

[Tha fios agaibh]

The SBL Channel. Remember? These have now been replaced - the Darlingtons came as a pair On-Line - very convenient. Because the L & R Signal tones from AUXL and AUXR actually get to the ADC IC30 (page 126/B6) at pins 1&2 - and leaving from pin9 as [DATAAD] but that's where I can no longer trace - so I'm in the dark as to whether IC30 is working or not - and likewise the following IC's through which the Digital Signal passes.

Yes I remember, but I can't imagine the Darlington final stage of amplification knocking out your line level signal so far up-circuit.
I understand wanting to see if IC30 is doing it's ADC job. By all means hook up your scope and see if you have a digital heartbeat. I would say to read the manual on your scope but alas the Chinese are not very good at writing manuals.

But, looking at another signal avenue.....I'm saying that it looks like IC801 should pass the analog signal to pins 20 and 23 provided the proper inputs are satisfied.
Take another look at 73's de Edd's mark-up of IC801 on this threads page 20.

There is a possibility that a menu or program setting is not right for the IC801 to pass the output. I may be all wet here, but it just seems to me that that should be checked first before wandering too far off into the digital abyss.

 

[Michael Studio1]

Yes I remember, but I can't imagine the Darlington final stage of amplification knocking out your line level signal so far up-circuit.
I understand wanting to see if IC30 is doing it's ADC job. By all means hook up your scope and see if you have a digital heartbeat. I would say to read the manual on your scope but alas the Chinese are not very good at writing manuals.

But, looking at another signal avenue.....I'm saying that it looks like IC801 should pass the analog signal to pins 20 and 23 provided the proper inputs are satisfied.
Take another look at 73's de Edd's mark-up of IC801 on this threads page 20.

There is a possibility that a menu or program setting is not right for the IC801 to pass the output. I may be all wet here, but it just seems to me that that should be checked first before wandering too far off into the digital abyss.

Yes, John, I wondered that. However, with this Denon just about 'anything goes'. I shall 'hook up my 'scope' and see whether there's anything there at pin9 of IC30.

This other signal avenue . . . you mean pins21 & 23 - FLOUT and FROUT - these are on their way to the 13pin connector in to the 7CH.Amp. I'm getting no Signal Tones there - which is what put me on the trail of the ADC in the first place - and to try and get some 'input' on whether this single channel Oscilloscope is able to detect these newly digitised tones.

On to 73's de Edd - I find the aspect of two differently pinned IC801's - one in the Cct Diag p114 and the other p168 very confusing. Both are shown as: R2A15218FP yet their pinouts are not the same! What gives? For a start look at pin53 on p168 - it 's called [ADCL] there. On p114 it's called N/C. And I dare say there are other anomalies. But one anomale is enough for me! ( FROUT & FLOUT are also different . . etc. )

As to the settings for the required Output, I am relying what is shown on the AVR Screen. Currently it shows: 'STEREO' 'VAUX' all of which tells me the switching should be directing the VAUXL and VAUXR inputs to the Default Output 'FL' & 'FR'. Michael Studio1 UK 12:32BST 17-05-2018

 

[Tha fios agaibh]

..you mean pins21 & 23 - FLOUT and FROUT - these are on their way to the 13pin connector in to the 7CH.Amp. I'm getting no Signal Tones there - which is what put me on the trail of the ADC in the first place - and to try and get some 'input' on whether this single channel Oscilloscope is able to detect these newly digitised tones.

On to 73's de Edd - I find the aspect of two differently pinned IC801's - one in the Cct Diag p114 and the other p168 very confusing. Both are shown as: R2A15218FP yet their pinouts are not the same! What gives? For a start look at pin53 on p168 - it 's called [ADCL] there. On p114 it's called N/C. And I dare say there are other anomalies. But one anomale is enough for me! ( FROUT & FLOUT are also different . . etc. )

As to the settings for the required Output, I am relying what is shown on the AVR Screen. Currently it shows: 'STEREO' 'VAUX' all of which tells me the switching should be directing the VAUXL and VAUXR inputs to the Default Output 'FL' & 'FR'. Michael Studio1 UK 12:32BST 17-05-2018

Yes, I mean pins 21 & 23. It'd be great if you could get an output on these pins. I would certainly try all the different input selections and settings to try and make that happen.

I can't explain the discrepancy between Ic801 on p114 and p168 but p114 should be trusted because that's the way it's wired.
Often the datasheet will call (recommend) a pin as one thing, but in actual use it may be labeled something else but inherently it functions the same. Pin 53 is ADCL, but on p114 it's labeled N/C meaning "no connection" because its not used.

What don't truck with me is pins 15 and 21 are shown as internally grounded on p168 but are SW and FL outputs back on p114.

 

[Michael Studio1]

Yes, I mean pins 21 & 23. It'd be great if you could get an output on these pins. I would certainly try all the different input selections and settings to try and make that happen.

I can't explain the discrepancy between Ic801 on p114 and p168 but p114 should be trusted because that's the way it's wired.
Often the datasheet will call (recommend) a pin as one thing, but in actual use it may be labeled something else but inherently it functions the same. Pin 53 is ADCL, but on p114 it's labeled N/C meaning "no connection" because its not used.

What don't truck with me is pins 15 and 21 are shown as internally grounded on p168 but are SW and FL outputs back on p114.

You've got the picture, John. It's truly bonkers. One could say 'misleading'.
Onward - by going backwards at the moment - I removed the HDMI_B'D to physically check the whereabouts of the IC's placed on the 'foil' side and to attach a few Tagged Test Tails, but when I replaced it in the 'stack' and turned the AVR back on, there was no signal at the two Caps C799 and C831. Probing with the DVM showed no power at those three 1.6A Fuses on the REG_CNT 1/4 (page110). This is odd, yet indicative of a possible causal problem - so it's exciting too. And that's where I left it last night. I was too tired to think straight. I will be doing investigative tests today and will post my findings. Never rains - but it pours! But here in Sussex-by-the-Sea we have a mini heat-wave. Michael Studio1 UK 06:03BST 18-05-2018

 

[Michael Studio1]

BTW - the Front Panel fired up OK and gave the expected STEREO VAUX as though all was well (but it isn't)

 

[Michael Studio1]

BTW - the Front Panel fired up OK and gave the expected STEREO VAUX as though all was well (but it isn't)

Turning on the AVR this morning, using the Error Checking Mode - page23 - only showed the Thermal history problem which resulted in my replacing those Darlington Xistors. The Signal tones are back at C799 and C831 so I'm back in business . . . but why no REG_CNT power yesterday? . . . I shall take advantage of a Power Up situation and do some tracing and power tests. Michael Studio1 UK 10:11BST 18-05-2018

 

[bushtech]

This intermittent business worries me. I saw on some forum somebody with a Denon had to plug/unplug a connection 3 or 4 times with a clean after every unplug before it started connecting reliably. Could a bad connection somewhere be triggering a protection circuit, of which the Denon apparently has plenty.
And I still think plugging it into a TV will help.

My 2c

 

[Michael Studio1]

Turning on the AVR this morning, using the Error Checking Mode - page23 - only showed the Thermal history problem which resulted in my replacing those Darlington Xistors. The Signal tones are back at C799 and C831 so I'm back in business . . . but why no REG_CNT power yesterday? . . . I shall take advantage of a Power Up situation and do some tracing and power tests. Michael Studio1 UK 10:11BST 18-05-2018

The two Signal Tones arrive at pin1 and pin2 of IC30 Good. Now to check the Power at IC30 pins 6&7 also 14&15. Found no Power at these pins. Therefore here is our initial problem. Must check 5V. rails next. This is an internal connection as shown on page127/N3 [FROMD.SUPPLY] also note directions on page128/N3 [TO D.SUPPLY] page129/I1 (or did I?) page117/N-D1 the D.SUPPLY/RESET. My suspicions are on [SWM5V] at page117/J7 and see what those Xistors TR16 and TR17 are up to. They are situated on the HDMI_B'D somewhere - go search! Power has gone. No readings (yet the Front Panel stays illuminated and shows: STEREO VAUX. So I am going around in circles - getting no-where. Michael Studio1 UK 11:26BST 18-05-2018