Denon AVR-1912 E2/EA

[Michael Studio1]

Best of luck!

or several metres of HDMI cable

Or fathom out how to feed HMDI into the Lab PC? But I must get on with my attempt at finding the cause for the non-working AVR! Michael Studio1 UK 15:55BST 09-05-2018

 

[Michael Studio1]

Back to work! I have injected two Signal Tones from the FeelTech Signal Generator into the VAUXL (500cps) and VAUXR (700cps) and have traced them with the Probe Amp. through C831 and C799 to pin 2(L) and pin 1(R) of IC20 which is the AD converter on page 126/B5. Thereafter these tones are in Digital format. The IC29 is a 48pin IC on page 126/G5 is the DAC and the Signal Tones should emerge as Analog at pin 1(LOUT1-) & pin 2(LOUT+) to feed IC28A(FL) page 126/K4 and IC28B(FR) page 126/K5 emerging as [DAFL]> and [DAFR]> (page 129/H3-5) CN2 Connector Block pin 28 [DAFL] and pin 26[DAFR]. CN2 connects with CP11 (page 112/J-L4) on the FRONT CONNECTOR. This traces down to CP115 pin 13 [DA_FL] and pin 12 [DA_FR]. This CP115 is connected with CN115 on page 114/F-G1 connecting to IC801 pin 93 [D/A_FL] and pin 94 [D/A_FR]. I'm going to rest my case here while I probe to see if it works this far! I dare say a few screen shots of all this might be appropriate but . . . I have been immaculate in my routing, I hope, and anyone with the Denon AVR-1912 Service Manual should be able to follow it - given all the page numbers and 'Grid References' . Michael Studio1 UK 17:46BST 09-05-2018

 

[Tha fios agaibh]

. Alternatively, you can use a composite cable (Yellow) to view it if you have a monitor with that type on input.
Use the top video output in picture.

Unfortunately, PC/computer graphics cards are generally just for output to a monitor unless it has a video capture (input) feature.

 

[Tha fios agaibh]

I know your injecting manually but the test tone Menu should look like this if interested:

 

[Michael Studio1]

I know your injecting manually but the test tone Menu should look like this if interested:

View attachment 40974

Thank you John. This is very interesting. I really must find that Remote Control! In the meantime I shall see whether my Test Tones have gone any further - and even be converted back to Analog - even though they are not getting to the FR and FL SPKR terminals. I must get back to testing the power supply voltages at the IC's.
Michael Studio1 UK 22:12BST 09-05-2018

 

[Michael Studio1]

I have another AVR (Pioneer) we use in our domestic sound system. It too has the white noise feature for testing the speaker outputs.

 

[Tha fios agaibh]

On my Avp, I know if it's not set up correctly a channel (speaker output) may not even work. For instance, the speaker selection can be set to "none", or the channel volume level could be set so low the output can barely be heard with the master volume knob turned all the way up.

Good luck with your search.
Under the couch pillows perhaps?
Lol.

 

[Michael Studio1]

On my Avp, I know if it's not set up correctly a channel (speaker output) may not even work. For instance, the speaker selection can be set to "none", or the channel volume level could be set so low the output can barely be heard with the master volume knob turned all the way up.

Good luck with your search.
Under the couch pillows perhaps?
Lol.

Hello John - Ah! But where is this Speaker Selector knob? I only seem to have an Input Selector knob and a Volume control. Maybe I'm guilty of not reading the Service Manual thoroughly enough? As for the Remote, I've sent a message to my son Maxim at University - since he brought this can o' worms home from there! Things a parent does! Michael Studio1 UK 08:23BST 10-05-2018

 

[Michael Studio1]

Now I have been totally disappointed. Whereas in my last post the signal tones were getting to the ADINL and ADINR, now they are not getting to either of those electrolytics I replaced - C799 and C831 (page 126/K3 & K3). They do get to the HDMI_B'D though - therefore something is horribly intermittent which is the worst of scenarios. It is quite possible that I shall give up on this - shame, after all the time spent and help you've all given - but the intermittent factor is one which will be found by sheer luck I believe. Michael Studio1 UK 16:30BST 10-05-2018

 

[Tha fios agaibh]

Michael, Try not to be disheartened.
This may not be that big of a deal. Perhaps a bad plug or ribbon cable? Take courage in the many successes you've had. Such as overcoming the protect mode, finding shorted mosfets, bad caps etc. If you discovered that you had your signal but IC801 was not proceeding it I'd but much more discouraged. (Blown major chip).

By all means take a break from it, so when you return to it, you'll have restored patience along with a fresh outlook.

 

[Tha fios agaibh]

But where is this Speaker Selector knob?

There's no knob. Its a function of the set-up mode that you follow on screen.
Example, (on my set-up) it walks you through it and asks you if your speakers are large or small, how many feet/meters away, and a number of other questions in order to customize output to your surroundings.

 

[Michael Studio1]

Michael, Try not to be disheartened.
This may not be that big of a deal. Perhaps a bad plug or ribbon cable? Take courage in the many successes you've had. Such as overcoming the protect mode, finding shorted mosfets, bad caps etc. If you discovered that you had your signal but IC801 was not proceeding it I'd but much more discouraged. (Blown major chip).

By all means take a break from it, so when you return to it, you'll have restored patience along with a fresh outlook.

Thanks for your encouragement, John. Within an hour I was back 'at it' trying to fathom 'what's up Doc?' So I have been making 'routing lists' of power and audio to attempt establish the 'why' and 'wherefore'. I shall continue today - I'm after the point where the audio stops before getting to those two caps C799 & C831. I'm probably back to a cracked pcb - or something similar. I'll post if anything found. Michael Studio1 UK 06:54BST 11-05-2018

 

[bushtech]

Michael, have you looked at page 22, 23 of the Manual. Maybe the Denon can tell you what's wrong

 

[Michael Studio1]

Michael, have you looked at page 22, 23 of the Manual. Maybe the Denon can tell you what's wrong

Thank you, Dries, I will look at those pages right away! Michael Studio1 UK 08:45BST 11-05-2018

 

[Michael Studio1]

This is Very Odd! Very Odd Indeed - I just turned on the AVR and the Signal Tones are back on C.799 and C831. Maybe I should 'rock the boat' a little to see if they disappear again - then I'll know there's a loose whatsit somewhere. In the mean-time, looking at those pages (22&23) I have never seen any errors displayed on the screen. Which is even Odder - isn't it! The AVR has been off all night, so I just turned it on and tested for 700cps and 500cps at the top of those two replacement Caps. For the tones can be heard (if they're there) by simply touching the Audio Probe on the can-covers of those replacement Capacitors - I don't know if the original Denon capacitor's covers were insulated - but the replacement ones aren't. Michael Studio1 UK 08:55BST 11-05-2018

 

[bushtech]

The errors are not automatically displayed. You have to go and look for them. Section 2.1 on page 23

 

[Michael Studio1]

The errors are not automatically displayed. You have to go and look for them. Section 2.1 on page 23

This is strange, Dries, and thank you for pointing this out - the strange part is that para.3 on p.23, I have already made a marginal not: "See Page 19" - I have therefore already been here - but (typical of me) I have forgotten about it. Slap on wrist &c. SO. . . . I must follow the procedure and see what comes up!. I think No.10 "Diagnostic Mode" is the one to go for. I will, before turning the AVR 'off' check that the signal tones are still audible at C799 & C831. later - Yes, they are. Michael Studio1 UK 16:09BST 11-05-2018

 

[Michael Studio1]

Later: So I activated the Special mode setting, it showed no change from the expected - i.e. STEREO VAUX. The tones were still at the two capacitors. I turned off the AVR again. Turning it on I invoked para.3 on Page 23. there I saw the same message shown last time I did this: PRT : THERMAL B . This was the result of frying those Power Xistors and 0.47Ω power resistors - all of which have now been replaced, of course. The Signal Tones are still arriving at C799 and C831. I have made out two routing plans for testing a) the audio (signal tones) and b) the Supply Voltages - ensuring with 'b)' that the IC's in the 'a)' route are getting the correct power as required on the Cct.Diags. They are. Then I was to check with the Audio Probe where the signals L&R had got to. The result has been: The two Signal Tones, having got through to IC801 (page114) (which shows IC801 is OK) eventually arrive through those two Caps. C799 and C831 at IC30 pin1[AINR] and pin2[AINL] here they are digitised and emerge at pin9[DATAAD] where I can no longer monitor as it's a digital signal. So all seems well up to this point. The digital signal then arr. at pin24 of IC as [DATAAD] I don't know what this IC does to the signal but it looks as though it comes out at pin21 as [DATADIR1] and thereafter gets lost . . . Michael Studio1 UK 17:47BST 11-05-2018

 

[Michael Studio1]

A small interesting N.B. I discovered that the Signal Tones had once again disappeared at C799 & C831 - and thought "here we go again" but then checked the AVR Power. It was OFF - Something must have upset it - again. Turning it on again the Tones were back at the Caps. Just a mental note to myself to check the power frequently!

 

[Tha fios agaibh]

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"