Denon AVR-1912 E2/EA

[Michael Studio1]

Meter's battery OK?

VERY strange. Yes, Bushtech, the UNI-T model UT61E battery is OK. I checked it with my other questionable DVM - the HoldPeak HP-9804. and it reads +9.4V. The UT61E is still questionable though and for the reason that when powered up with no test probes in and Volts selected (this setting gives DC reading unless the blue button is pressed - then it goes into AC setting). The oddity in the DC setting (with no probes in) is that sometimes it shows a Neg. sign before the readout - then that disappears and all is well. Right now it is reading as it should - so I'll make another round of the 'Tagged Test Tails' on the AVR and include readings from the Thandar TM531 Digital Multimeter and post the results here:
All readings are referenced to AGND CN101 pin 5 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . UNI-T UT61E . . . . THANDAR TM351 . . . . . . . . . . . . .
CP13A pin7 SIDE_CON B'D. . page 111 . . = +8.16V. .. . . . . . . . = +8.11V . . . . . . . . . . . . . . . . . . .
. . " . . pin6 . . . . " . . . .. . . . . . . . ." . .. . . . . = -7.829V. . . . . . . . . = -7.89V. . . . . . . . . . . . . . . . . . . .
CN14 . pin15 . . . ." . . . . . .. . . . . . " . . . . . . . = +6.858V. . . . . . . . .= +6.78V. . . . . . . . . . . . . . . . . . . .
CN101 pin1 . .REG_CNT 1/4 . . page 110 . .= +14.22V. . . . . . . . .= +14.2V. . . . . . . . . . . . . . . . . . . .
IC 103 pin1 . . . . . . " . . . . . . . . . " . . . . . . . = +6.386V. . . . . . . . . = +6.3V. . . . . . . . . . . . . . . . . . . . .
. . " . . .pin3 . . . . . . . ". . . . . . . . . " . . . . . . . .= +6.61V. . . . . . . . . .= +6.53V. . . . . . . . . . . . . . . . . . .
IC 104 pin1 . . . . . . ." . . . . . . . . . " . . . . . . . = +3.6V. . . . . . . . . . = +3.52V. . . . . . . . . . . . . . . . . . . .
. . " . . pin3 . . . . . . " .. . . . . . . . . " . . . . . . . = +4.3V. . . . . . . . . . . = +4.22V.. . . . . . . . . . . . . . . . . . .
IC 105 pin1 . . . . . . ." . . . . . . . . . " . . . . . . = +8.168V. . . . . . . . ..= +8.12V. . . . . . . . . . . . . . . . . . . .
. . " . . pin3 . . . . . . . " . . . . . . . . . " . . . . . . .= +5.121V . . . . . . . . = +5.07V. . . . . . . . . . . . . . . . . . . .
IC 107 pin1 . . . . . . . " . . . . . . . . . " . . . . . . . = +0.002V. . . . . . . . .= -0.05V.. . . . . . . . . . . . . . . . . . . .
. . " . .pin3 . . . . . . . " . . . . . . . . " . . . . . . . .= -7.838V. . . . . . . . . = -7.9V. . . . . . . . . . . . . . . . . . . . .
IC 106 pin1 . . . . . . . " . . . . . . . . . " . . . . . . .= +14.15V. . . . . . . . .= +14.14V. . . . . . . . . . . . . . . . . . .
. . " . . pin3 . . . . . . ." . . . . . . . . . ." . . . . . . .= +8.169V. . . . . . . . . = +8.13V.. . . . . . . . . . . . . . . . . . .

That's it. I hope it makes sense and that I can continue to the next step. Are these Voltages as expected?
Signal Tones. Once more I am injecting 700Hz into VAUXR and 500Hz into VAUXL. These Tones are getting through the CX4 ffc cable and into the HDMI_B'D - but no further. Reason: only +3.59V at IC801 pin80.
Michael Studio1 UK12:05GMT

 

[Tha fios agaibh]

Goodness. I'm getting lost in a sea of numbers.
So, are we back to where we were before?
When you were getting +8 cp14 pins 14,15 and -8v pins 16,17 and at the top (cathode) of D801 But then losing the -8v on the bottom (anode) side of the diode?

On Ic107 you say your getting .002v on pin one, That's the input side right? What is the voltage on the output side? what is the voltage across the input and output pin?

 

[Tha fios agaibh]

I thought I was onto something for a minute. Looking at Ic 107 data sheet pin 1 is Com (ground) pin2 is In and pin3 is the Output. So any measurements to pin1 are of no help.
What is the voltage of pin2 to ground?
What is the voltage of pin 3 to ground?

 

[73's de Edd]

Sir Michael . . . .

You did reveal readings of the circuitry that the two voltages were derived from as CN13, in its having proper +8 and -8 VDC on their pins 6 and 7.
On the raw DC from the rectifiers that is coming in to make the Plus and Minus 8VDC supplues, they are initially labeling those lines as Plus and Minus 8VDC, whereas, their actual voltage are being the Plus and Minus 14.2 VDC's that you are reading.
NOW . . . .
Your IC 103 voltages are wrong . . . shud be +5VDC output.
Your IC 104 voltages are wrong, but I believe that you are thinking that the pin outs of a 7800 series NEGATIVE regulator and a POSITIVE are being the same . . .they are NOT ,check them out.
Your IC 105 voltages look correct.
Your IC 106 voltages look correct.
Your IC 107 voltages are wrong, but I think that it is also being a pin misread, as was done on IC104.

73's de Edd
.....

 

[Tha fios agaibh]

I thought I was onto something for a minute. Looking at Ic 107 data sheet pin 1 is Com (ground) pin2 is In and pin3 is the Output. So any measurements to pin1 are of no help.
What is the voltage of pin2 to ground?
What is the voltage of pin 3 to ground?

Sorry, wrong datasheet.

 

[Tha fios agaibh]

IC 107 voltages are wrong, but I think that it is also being a pin misread, as was done on IC104.

Good catch de Edd, the positive 7800 series has pin 1 for input while the negative 7900series has pin 2 for its input. Both use pin 3 for Output.

 

[Michael Studio1]

If you read improper polarities right at the 7000 series voltage regulators, and if you are using an autoranging meter, will you now look down and check the leads plugging into the meter to see if they might be reversed there ? ( ¿¿¿ BLUSH-BLUSH ??? )
Then . . . pull out a standard 9V rectangular battery and inspect the battery contacts vewy-vewy cawefully . . . .a la Elmer Fudd .
Out-ee is being the battery POSITIVE
and
In-ee is being the battery NEGATIVE
And see if that then reads right on your DC metering.

And yes . . . .the connector of the:
RC5/M-X PORT
REG-CNT 4/4 B3
does not have an Agnd pin connection on it, so you would rely upon a negative metering connection being from one of the other modules A gnd connections.

73's de Edd
.....

Thanks 73's de Edd. Your profound knowledge is necessary here! As you may have read it was the UNI-T meter at fault - which fault seems now to have cleared itself!! So I am now using it in tandem with the Thandar351 Digital Multimeter. I posted my latest readings above - but my careful layout got lost in translation and what appears is quite a mess. Sorry. It seems that 'space' on this site is a no-no. So, in order to make sense of it I have to fill that space with, say, dots . . . . . - or rather ................ Yes? And, 'Yes' the UNI-T is Autoranging. as you suggest.

My apologies for not suggesting that you verify your oddball voltages with another meter.
Congrats on discovering it.

Goodness. I'm getting lost in a sea of numbers.
So, are we back to where we were before?
When you were getting +8 cp14 pins 14,15 and -8v pins 16,17 and at the top (cathode) of D801 But then losing the -8v on the bottom (anode) side of the diode?

On Ic107 you say your getting .002v on pin one, That's the input side right? What is the voltage on the output side? what is the voltage across the input and output pin?

These IC's (page 180) 103, 105,106 are NJM7800 series pin1 IN, pin2 - GND, pin3 - OUT. IC104 and 107 are NJM7900 series - and I had mistakenly thought they have the same pinout. But no! You are correct (mea culpa) Now I shall re-measure the two IC's and correct that chart!

 

[Michael Studio1]

Sir Michael . . . .

You did reveal readings of the circuitry that the two voltages were derived from as CN13, in its having proper +8 and -8 VDC on their pins 6 and 7.
On the raw DC from the rectifiers that is coming in to make the Plus and Minus 8VDC supplues, they are initially labeling those lines as Plus and Minus 8VDC, whereas, their actual voltage are being the Plus and Minus 14.2 VDC's that you are reading.
NOW . . . .
Your IC 103 voltages are wrong . . . shud be +5VDC output.
Your IC 104 voltages are wrong, but I believe that you are thinking that the pin outs of a 7800 series NEGATIVE regulator and a POSITIVE are being the same . . .they are NOT ,check them out.
Your IC 105 voltages look correct.
Your IC 106 voltages look correct.
Your IC 107 voltages are wrong, but I think that it is also being a pin misread, as was done on IC104.

73's de Edd
.....

Hello and Thanks 73's de Edd. I have made many corrections to my many errors and tried to upload them in a tabloid form - but this programme will not accept the changes. So in direct reply to your queries, here are the values I found. 1st. there are two different series of IC's. This I discovered and changed my approach accordingly. I had just about given up trying to post these readings to the Forum since they were not accepted in the form I was using. Now I have these readings:
IC 103 and 104 are referenced to VGND. so:
IC 103 pin 1 = +2.76V pin 3 = +2.98V
IC 104 pin 2 = +0.53V pin 3 = +0.67V
IC 105, 107 and 106 are referenced to AGND so:
IC 105 pin 1 = +8.17V pin 3 = +5.12V
IC 107 pin 2 = -14.85V pin 3 = -7.84V
IC 106 pin 1 = +14.15V pin 3 = +8.17V
But the reading at IC801 pin 80 is only +3.63V. so that IC isn't fired up.
Michael Studio1 UK 17:51GMT Jacobean uprising around that year!

 

[Tha fios agaibh]

Michael, I presume you have good voltages everywhere except at the bottom of D801 (anode) where your -7v disappears. Like we had before the meter faux pas?

With no power applied and connections unhooked, you could check the ohm readings from bottom of D801 to Agnd to see if there's low resistance. Now,
Try removing R883 resistor on page 114. Looks like a 0Ω resistor feeding some transistor cks.
Doesn't look like that many things on the same node as D801 anode that could be robbing the voltage..

 

[Michael Studio1]

Michael, I presume you have good voltages everywhere except at the bottom of D801 (anode) where your -7v disappears. Like we had before the meter faux pas?

With no power applied and connections unhooked, you could check the ohm readings from bottom of D801 to Agnd to see if there's low resistance. Now,
Try removing R883 resistor on page 114. Looks like a 0Ω resistor feeding some transistor cks.
Doesn't look like that many things on the same node as D801 anode that could be robbing the voltage..

Thank you, John. But before I try to find R883 I must try AVCC pin 30 on IC801 for I had got a fixation about pin 80 on IC801 - which is non-sense as this is NC (according to the scriptures. 1/2 a mo . . . . suddenly there's +7.41V. at pin 30 - the AVCC Supply Voltage. Maybe it's because I am listening to Symphony No.2 by George Enescu on my Sony portable CD player . . . Who can tell? Michael Studio1 UK 18:42GMT

 

[Michael Studio1]

So I now have to probe for my VAUXL 500 cps and VAUXR 700 cps signal tones. Not getting far. Too tired. STOP.
Michael Studio1 UK 19:32GMT

 

[Michael Studio1]

Michael, I presume you have good voltages everywhere except at the bottom of D801 (anode) where your -7v disappears. Like we had before the meter faux pas?

With no power applied and connections unhooked, you could check the ohm readings from bottom of D801 to Agnd to see if there's low resistance. Now,
Try removing R883 resistor on page 114. Looks like a 0Ω resistor feeding some transistor cks.
Doesn't look like that many things on the same node as D801 anode that could be robbing the voltage..

GOOD NEWS!! at last:
John. This is a 'New Era' We do have Voltages. (page 114) I have first measured the voltages on either side of the two Diodes: D800 - Anode = +8.16V.
Cathode = +7.42V.
D801 - Anode = -7.06V.
Cathode = -7.82V.
Now IC801 pin 30 (AVCC) = +7.41V.
pin 52 (AVEE) = -7.058V.
I need steering in the direction I should next go. Do I apply the two Signal Tones to VAUXL & VAUXR? Is this 'Good Friday' or am I pushing my luck?
Michael Studio1 UK 10:51GMT

 

[Michael Studio1]

Applied 500cps > VAUXL and 700cps > VAUXR = both tones appear at CX4 pins 6&8 >
Page 129 CN2 pins 4&6 OK then the tones disappear. Next I trace the Ccts L&R to CP11 pins 4&6 > CP114 pins 17&18 > (Page 114) CN114 pins 17&18 > IC801 pins 83&84 > through IC801 to pins 55&54 A/D_R & A/D_L >
CN115 Pin 15 A/D_R & Pin 17 A/D_L > CP11 Pin 30 (ADINR) & Pin 32 (ADINL) > (CP11 mates with CN2)
(page 129) CN2 pin30 = ADINR and CN2 pin 32 = ADINL > page 126 = MAIN_DAC B'D where both L&R end up in IC30 to be converted to Digital.
I shall now reassemble the PCB cage to find where, exactly, those tones disappear . . . .
Michael Studio1 UK 14:13GMT

 

[Michael Studio1]

I have traced the L&R tones into IC30 (page130) and can go no further as this is where A/D happens. Interestingly, this is 'where we came in' all that time ago, for the LEFT tone has disappeared but the RIGHT tone has got to FRONT SPKR RIGHT. Originally 'twisting' the PCB 'cage' would cause the Right tone to appear - and this was the original problem. So at least I've returned to my origin! Any ideas out there at this significant juncture?
Michael Studio1 UK 14:41GMT

 

[bushtech]

Twist the PCB 'cage

Sorry, couldn't resist that

 

[Michael Studio1]

Twist the PCB 'cage

Sorry, couldn't resist that

Did that! Didn't work though . . .

 

[Michael Studio1]

I am seeing things incorrectly and my approach should be more simple. First, both Left AND Right channels ARE getting to IC30. Now I must think Digitally! In the Studio we record Digitally. (thought processes are going on here) Digital OUT contains both Left and Right and is connected by Toslink cables to the RAW - in our case a Lynx TWO/A with a Lynx 'daughter-board' - capable of handling 16 Channels - all Digital.- at 48 kHz. One can, of course, assign Left or Right - or Centre - whatever to these channels and Microphone placing will be accordingly made. This is a very round-about way of saying the single Toslink cable will be carrying both Left and Right Channels in Digital format. ergo IC30 'OUT' will be handling both Left and Right and the problem here is not Digital - and must be in the 7 Channel Amp. somewhere. N'est ce pas?
Michael Studio1 UK 08:00GMT

 

[bushtech]

Michael, please correct me if I'm wrong. I thought you were looking for an intermittent Aux L. Is Aux L an analog out. Is that now working?

 

[Michael Studio1]

Michael, please correct me if I'm wrong. I thought you were looking for an intermittent Aux L. Is Aux L an analog out. Is that now working?

Hello Bushtech - thanks for coming in on this. There is no analog AUX Out. What happens is that, by default, the input AUXL & AUXR become FRONTR and FRONTL at the back of the unit. This is switchable on the front panel. But, for simplicity, I leave it in Default.
So back to the problem: VAUXR is getting right through to FRONT(R) by default, but VAUXL is only getting as far as IC30 pin 2.[AINL] where I can hear it with my amp.probe (Page 126/B5). Looking physically now at the 7CHANNEL B'D in the Unit each of the 7 Channels has a 3 pin Test Point - see Page 106/I2 (that's a cap.'i' not a one) for FL and /I5 for FR &c. (it continues on Page 127, of course). I must find out waht to expect at these TP401 to TP407. There has to be a reference to it somewhere in this Service Manual. Michael Studio1 UK10:08GMT

 

[Michael Studio1]

for 'RAW' read 'DAW' - the time limit expired for Edit.