Denon AVR-1912 E2/EA

[Michael Studio1]

I notice that the DA+5V. is referenced to DGND - as shown around IC30 Page 126/B5. I'm about to check the Voltage at IC30 pins6/7&14/15 page126/B5 ref. DGND. OK. All four pins of IC30 read: +1.48V. and this comes from CN3pin6/7 Page 129/N3 which reads: +1.49V. I will trace it further after Breakfast! Michael

 

[Michael Studio1]

CN3 pins6/7 Page 129/N3 come from SIDE CONNECTOR page111/G6 CP3 pins6/7 from CP13/A pin10 - from: REG_B'D. page110/B5 CN13A pin10 from the IC105 Cct./E4. I will look at a spec sheet for NJM7805FA. Michael.

 

[Michael Studio1]

The A+8V. from IC106 (page110/H4) at CN13A pin7 page110/B4 reads: +4.52V. The rail which supplies IC106 comes from CP101 pins1/2 : CN101 pins1/2 - page110/K8 - which I had previously measured at +14.2V. ref. A-GND is +10.69 whilst CN101 pins8/9 - page 110/K8 read: -18.75V. It seems the balance between the + & - has shifted. Is this possible? I must check Fuses 107 & 108. These look like red resistors and are both OK. The Spec sheet for the 3-Terminal Positive Voltage Regulator shows Vin (max rating) = 35V. Michael Studio1 UK 16:51BST 30-05-2018

 

[Tha fios agaibh]

I notice that the DA+5V. is referenced to DGND - as shown around IC30 Page 126/B5. I'm about to check the Voltage at IC30 pins6/7&14/15 page126/B5 ref. DGND. OK. All four pins of IC30 read: +1.48V. and this comes from CN3pin6/7 Page 129/N3 which reads: +1.49V. I will trace it further after Breakfast! Michael

No, it's referenced to DAgnd. Dgnd is not directly coupled to the source ground, so forget about it in the matter of powering IC30 for the moment.
Put your positive dvm lead on IC30 pin 6 or 7. Then, with your black neg lead, probe Agnd or DAgnd to see where your losing your ground. If you have nothing, put your neg lead on IC30 pin 8 or 18 (DAgnd) and with your red pos lead probe along DA+5v to see where your losing it.

 

[Michael Studio1]

No, it's referenced to DAgnd. Dgnd is not directly coupled to the source ground, so forget about it in the matter of powering IC30 for the moment.
Put your positive dvm lead on IC30 pin 6 or 7. Then, with your black neg lead, probe Agnd or DAgnd to see where your losing your ground. If you have nothing, put your neg lead on IC30 pin 8 or 18 (DAgnd) and with your red pos lead probe along DA+5v to see where your losing it.

Thanks, John, for a way forward. This is really appreciated. I shall print your reply and put it to use. Right now I'm making a Microphone Stand adaptor in my Lathe - I have to drill out and bore into a short piece of 1" bar to make a 3/4" deep x 0.7" dia hole - and then screw-cut in that hole a very odd thread of 1.0mm Metric (= t.p.mm instead of the usual t.p.i.) Then I can use my third Electro-Voice RE55 mic in a 3-mic in-line array to record a Symphony Orchestra. That's just another thing I do! Now. Back to the AVR. Michael Studio1 UK 20:32BST 30-05-2018

 

[Tha fios agaibh]

Thanks, John, for a way forward. This is really appreciated. I shall print your reply and put it to use. Right now I'm making a Microphone Stand adaptor in my Lathe - I have to drill out and bore into a short piece of 1" bar to make a 3/4" deep x 0.7" dia hole - and then screw-cut in that hole a very odd thread of 1.0mm Metric (= t.p.mm instead of the usual t.p.i.) Then I can use my third Electro-Voice RE55 mic in a 3-mic in-line array to record a Symphony Orchestra. That's just another thing I do! Now. Back to the AVR. Michael Studio1 UK 20:32BST 30-05-2018

That is an odd size. Closest I could come is a 11/16-24 tap.
Lets get this AVR going so you can be listening to your opera recordings in surround sound.

 

[Michael Studio1]

No, it's referenced to DAgnd. Dgnd is not directly coupled to the source ground, so forget about it in the matter of powering IC30 for the moment.
Put your positive dvm lead on IC30 pin 6 or 7. Then, with your black neg lead, probe Agnd or DAgnd to see where your losing your ground. If you have nothing, put your neg lead on IC30 pin 8 or 18 (DAgnd) and with your red pos lead probe along DA+5v to see where your losing it.

Thanks, John - here are my findings: Pos.dvm on IC30 pin6 & Neg.dvm on AGND = 0 Neg.dvm on DAgnd = 1.49V. Neg.dvm on IC30 pin8 = +1.48V. or pin16 = +1.48V. Neg.dvm on IC30 pin16 & Pos dvm on DA+5V = 1.5V. But back to that "CN101 pins1/2 - page110/K8 - which I had previously measured at +14.2V. ref. A-GND is +10.69 whilst CN101 pins8/9 - page 110/K8 read: -18.75V. It seems the balance between the + & - has shifted." Any thoughts on this? Michael Studio1 UK 22:37BST 30-05-2018

 

[Michael Studio1]

That is an odd size. Closest I could come is a 11/16-24 tap.
Lets get this AVR going so you can be listening to your opera recordings in surround sound.

Agreed. I'm being dictated to by the Mic stand thread - extremely odd - also because it's tapered! It'll be a Youth Orchestra I'm recording on 29th. June in the Town Hall, LEWES (East Sussex). Michael

 

[Tha fios agaibh]

Thanks, John - here are my findings: Pos.dvm on IC30 pin6 & Neg.dvm on AGND = 0 Neg.dvm on DAgnd = 1.49V. Neg.dvm on IC30 pin8 = +1.48V. or pin16 = +1.48V. Neg.dvm on IC30 pin16 & Pos dvm on DA+5V = 1.5V. But back to that "CN101 pins1/2 - page110

First part good.
Then you lost me, what the heck are you on cn101? Lol
Our focus needs to br on DA+5v which starts at regulator IC105 on page110.

You should have 5v on CN13A pin 10 (DA+5v) with respect to Agnd on pin 4,5 (Agnd) Yes?

 

[Tha fios agaibh]

If you do have your DA+5v on CN13A....
Keep your Neg(black) dvm lead on pin 4 or 5 (Agnd) of CN13A and move your Pos (red) lead over to IC30 pin 6 or 7 to see if DA+5v is reaching all the way to its destination.

 

[Michael Studio1]

If you do have your DA+5v on CN13A....
Keep your Neg(black) dvm lead on pin 4 or 5 (Agnd) of CN13A and move your Pos (red) lead over to IC30 pin 6 or 7 to see if DA+5v is reaching all the way to its destination.

Thanks, John, Yes I do have +5.1V on CN13A pin 10 ref. pin 5. - Sorry, I've just got up and missed a Post from you. - Keeping Neg. on pin5 13A and moving Pos dvm to IC30 pin 6 or 7 = +5.1V.

First part good.
Then you lost me, what the heck are you on cn101? Lol
Our focus needs to br on DA+5v which starts at regulator IC105 on page110.

You should have 5v on CN13A pin 10 (DA+5v) with respect to Agnd on pin 4,5 (Agnd) Yes?

Thank you, John - Yes. I get 5.1V at IC30 pin 6 or 7 - thinks . . . has this rectified itself? Am going to see if the Signal Tones have come back to IC30 pins 1&2 . . No - they haven't. re: CN101 there was an enormous disparity in the raw +8V and -8V there. Michael 06:19BST

 

[Tha fios agaibh]

Almost, Now do the opposite. put your red positive dvm lead on CN13A for DA+5v (I forgot pin#) and then move your black neg lead from CN13A pin 4 or 5 (Agnd) over to points along Agnd and eventually DAgnd to find out where your losing the Gnd.
If it magically reappeared, I'd try wiggling around connections while your measuring voltage to try and find out why/where it keeps dropping out. Hammer out one problem before moving on or it'll rear its ugly head again.

 

[Michael Studio1]

Almost, Now do the opposite. put your red positive dvm lead on CN13A for DA+5v (I forgot pin#) and then move your black neg lead from CN13A pin 4 or 5 (Agnd) over to points along Agnd and eventually DAgnd to find out where your losing the Gnd.
If it magically reappeared, I'd try wiggling around connections while your measuring voltage to try and find out why/where it keeps dropping out. Hammer out one problem before moving on or it'll rear its ugly head again.

Thanks, John, for these helpful suggestions. But I've got bogged down looking at the Cct.Diags. which, being on so many pages, is quite problematic to come to terms with. I have been attempting to master the art of following the AGND & DAGND Ccts where they apply to IC30. Unfortunately I haven't yet 'got there'. However I feel I'm on the cusp of a break-through and shall continue after a break - during which I am turning two Microphone Stand adaptors in my 3 1/2" lathe. These are the adaptors requiring a thread of 1.0mm X 3/4" dia (o.d.). This I will have to bore, undercut and thread in the lathe. The other end is a 3/8" Whitworth spigot - standard European Microphone-stand size. This'll take me back to the Fifties' when I did a lot of this Centre-Lathe Turning. Michael Studio1 UK 20:04BST 01-06-2018.

 

[Tha fios agaibh]

Very good. I know how you feel, it can be frustrating at times but you just have to take it one step at a time.

Here's what we know:
What we're trying to do is power up IC30.
We've established that we are getting DA+5v all the way to IC30 on pin 6,7.

Presumably, that means the (DAgnd) ground doesn't reach all the way to IC30 pins 8,16.

You could power down check for continuity along DAgnd and Agnd which should be connected together at CP11 (see p.112).

Or, trace Voltage in the method I mentioned earlier.
We know you have Agnd back on CN13a (ref to DA+5v), now, try any other Agnd or DAgnd path, and try and find out where your looking it.

As far as the Microphone, your on your own.

 

[Michael Studio1]

Very good. I know how you feel, it can be frustrating at times but you just have to take it one step at a time.

Here's what we know:
What we're trying to do is power up IC30.
We've established that we are getting DA+5v all the way to IC30 on pin 6,7.

Presumably, that means the (DAgnd) ground doesn't reach all the way to IC30 pins 8,16.

You could power down check for continuity along DAgnd and Agnd which should be connected together at CP11 (see p.112).

Or, trace Voltage in the method I mentioned earlier.
We know you have Agnd back on CN13a (ref to DA+5v), now, try any other Agnd or DAgnd path, and try and find out where your looking it.

As far as the Microphone, your on your own.

Yes - and that's fine! = Mono! Back to AVR - Your suggestion is just what I am up to - tracing DAgnd. Will post when something positive occurs! And 'Yes' IC30 is getting +5V - but wrong GND. Michael Studio1 UK 07:44BST 02-06-2018

 

[Tha fios agaibh]

Not really wrong ground, it's just not making it all the way to IC30 like it should. Remember, Agnd and DAgnd should be the same.
Good luck.

 

[Michael Studio1]

Not really wrong ground, it's just not making it all the way to IC30 like it should. Remember, Agnd and DAgnd should be the same.
Good luck.

Thanks, John. for your timely reminder "Agnd and DAgnd should be the same". Interesting note coming up: I am getting a bit confused with the naming of the GND pin Page114/E2, CP14 pin18/19 = AGND shortly to be morphed to RET_GND and again morphed to AGND into IC801 pins: 4,7,10,16,19 then morphed yet again to DGND at pin48. Still, what's in a name? I must find the route taken by GND (whatever its prefix) from Page126/B5-6 = IC30 through to its Agnd on page110/B5 = CN13A pin 4&5. To do this I may need to add a few 'Test Tails'. Michael Studio1 UK 16:57BST 02-06-2018

 

[Tha fios agaibh]

As long as they connect, disregard the names. Sometimes the IC pin says one thing and the plug connections say another.

You could power down and turn on the audible beep on your dvm for checking continuity. It makes checking easier because you don't have to look at the meter.

 

[Michael Studio1]

As long as they connect, disregard the names. Sometimes the IC pin says one thing and the plug connections say another.

You could power down and turn on the audible beep on your dvm for checking continuity. It makes checking easier because you don't have to look at the meter.

Thanks, John, I'll do just that. Michael

 

[Michael Studio1]

There is an 'OPEN' between Page110 CN13A pin5 and: Page126 IC30 pin8. Thanks to your suggestion, John - to use the audible function on my dvm. Now all I have to do is find it (and fix it) Michael 07:54BST 04-06-2018