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Thanks John - that really proves all GNDS are at the same potential! I have the four connecting pcb's out on the bench now for continuity tests - HDMI, Front AND side CONNECTOR and AV_B'D. The +5V is arriving, but no GND at IC30 - I'm going to test whether the same applies to IC801 while I have those pcb's on the bench - and accessible. Michael 09:02BST
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Meanwhile with the 'stack' assembled on the bench and access to CP13A pin4&5 page111/D10 = AGND, measuring Ω to CP11 page 112 - (any odd numbered pin = GND) - I get ~120MΩ. So must check continuity between these two points. It should be '0'. Michael Studio1 09:27BST 04-060-2018
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Not all but yes Agnd and DAgnd.
So "CP11" is one end of a ribbon cable?
What was that other cable called, Flat cable?
I forgot the acronym for it.
Just saying if you found one bad cable, there could be others.
What was that other cable called, Flat cable?
I forgot the acronym for it.
Just saying if you found one bad cable, there could be others.
No, the long ribbon that I replaced was a 40 x way 'FFC' or ffc - the acronym for 'flat flexible cable' (I think) And that's the CX4 cable as shewn on Page129/N6-9. So the problem isn't with that. (phew!) The problem is between CP13A pin4&5 page111/D10 where my TestTail is soldered to, and any odd GND connection on CP11 page112 on the FRONT_CNT B'D. pin33 to which I have a TestTail soldered. It's a bit of a dodgy issue in this multi-page Cct.Diag. finding the actual routing connecting CP13A pin4 to CN11 pin33. Do ALL the GND connections emanate from CP13A? Or is the GND for IC30 and IC801 coming from different places? Michael Studio1 UK 20:33BST 04-06-2018
Easy to ge lost in the Gnd labyrinth.
I suspect cp11 because that's where DAgnd and Agnd converge.
Heres the path I see:
CP13A goes through SIDE_CNT boardCP13A to CN14 pin 4, which feeds through (p.114) to CN115 pins 5,8,11,14,16 which feeds through to CP11 (don't follow pins 5,7) pins 9,11,15,17,19,21,23,25,27,31,33
Also notice that on p.114 that Agnd also becomes Chassis Gnd. That makes for a convenient reference point.
So, put one lead of your continuity tester to chassis and let us know which CN/CP connection isn't playing along with our Gnd labyrinth.
I suspect cp11 because that's where DAgnd and Agnd converge.
Heres the path I see:
CP13A goes through SIDE_CNT boardCP13A to CN14 pin 4, which feeds through (p.114) to CN115 pins 5,8,11,14,16 which feeds through to CP11 (don't follow pins 5,7) pins 9,11,15,17,19,21,23,25,27,31,33
Also notice that on p.114 that Agnd also becomes Chassis Gnd. That makes for a convenient reference point.
So, put one lead of your continuity tester to chassis and let us know which CN/CP connection isn't playing along with our Gnd labyrinth.
Ok. I had it in my head that CP meant a connection plug that's a flex jumper cable.
I guess these "plugs" are the ridged front and side connection boards that interconnect the boards. Is that right?
If hunting down that gnd connection really becomes that much trouble, I'd say screw-it, and just put a jumper wire from point "A" to "B" to resolve the lost connection.
The whole point here is to get this thing working. Who cares if there's an extra wire routed across the pcb?
Thanks, John. re: "plugs" Denon seem to use "CN" in conjunction with "CP" - but beware! sometimes a CN# doesn't relate with a CP#! - such as Page129/H3, CN2, which is renamed CP11 on Page112/JKL3. These people create worms and put them in cans called AVR. Those board Connectors which hold the 'stack' together are impossible to find. I was looking for a source of this plocketry to make up that Test Jig for Servicing (Page43) but couldn't find the manufacturer. I have put the dvm in continuity mode and checked the GND pins you suggested to Chassis GND. The 'stack' being out of the chassis I'm connecting to the bare stranded I used to make continuity between all sockets so the AVR stays on without the back-plate being in place. I take it the Agnd becomes Chassis Gnd on Page114 at JK100 - the 6 (pair) jack Audio IN. What is the correct interpretation of "OPEN" - as on Page114/O7 C891OPEN -> CHASSIS? Does "OPEN" mean "It doesn't exist"? Also you say "(don't follow pins 5,7)" pin7 on CN115 is DA_SL. All tests show OK. None are OPEN Cct. But I must now try re-checking my findings of yesterday when I found CP13A pin4&5 page111/D10 = AGND, measuring Ω to CP11 page 112 - (any odd numbered pin = GND) - I get ~120MΩ. So must check continuity between these two points. It should be '0'." But it isn't. I must check, on Page110/K8/9 CN101 Agnd - even go back to CP104 pin2 and check there. Michael Studio1 UK 10:12BST 05-06-2018
Yes, I believe so. But note that the chassis Gnd does exist on p.114 A-5, and A-7.
Can you state this in a simpler way.
From Chassis Gnd to CP13A, I get X Ω
From Chassis Gnd to CP11, I get XΩ
That, John, is conclusive. Thanks for that. I have ground to a halt here again and am unsure of the way forward. I have been doing continuity tests on the 'stack' on the bench all day, based on following the path of Agnd: from CP13A pin4 to CN14 pin18. I cannot tie in a Gnd path to IC30. neither is there continuity between p114.CP14 pin18 and IC801 pins48/22. Something is amiss but I cannot tell what it is. You called it a 'labyrinth' - I'm calling it a 'jungle'. But what's in a name? I suppose I could make continuity tests on individual pcb's from the 'stack' and see if it comes together that way. But there's no identifiable open Cct. showing up so far. I'm doing better with the mic stand adaptor than the AVR. Michael Studio1 UK 19:55BST 05-06-2108
Thanks, John. I was testing the resistance from 13A pin4 to all the Odd numbered pins of CP11 - the readings are not all the same, but are approximately 120MΩ. I was expecting 0Ω. That's what threw me. I will reassemble the 'stack' and conduct that same resistance test. OK. This resistance test is totally bonkers. It is rising all the time as though a capacitor was being charged. The result is unsteady and inconclusive and around 150.0MΩ - and rising. Michael
Like I said, just go from chassis ground and document what isn't ringing through.
I see. Anything below about 10Ω I'd consider continuity. And anything above that,we'll call open circuit. If you read anything KΩ or MΩ, that's certainly open circuit. Don't over think the exact fluctuating number.
But Yes, We do need to find where we are losing this connection. We'll call CN13A in the open ground category.
But Yes, We do need to find where we are losing this connection. We'll call CN13A in the open ground category.
Thanks, John. I think I have been attempting a too complex test strategy. I will try to resolve each pcb first - and see what I come up with - then rebuild the 'stack' to include the two interconnecting REGULATOR_B'D pcb's. This will include the CN/CP13A connections and 4pin CN/CP13B connection. Michael Studio1 21:02BST
OK. I'm testing the AV_B'D and the HDMI_B'D against Chassis Gnd. The result is that all designated gnd pins give a beep. Now the 'stack' is reassembled and the only GND pin not giving a beep is CN/CP13A pin4/5. So the problem is in the CN13Apin4/5 path to Chassis GND. (somewhere) Michael Studio1 22:29BST 05-06-2018 finished for today .. . . . . .
Great, now moving along one side (upstream or downstream) of CN13A see if you can pick it back up. If not readily accessible, move on to the other side.
Now try an discern if we're getting it again left or right of CN13A
That's a terrific suggestion, John. Thanks. I imagine this series of tests for Chassis Gnd. can be done on the bench with the 'stack' of pcb's outside the chassis? The 'stack' consists of: HDMI, AV, SIDE_CONT., FRONT_CONT., and REGULATOR B'D with REG_CNT. These B'D's are all connected together but there's no Xfmr connected (obviously) Michael 08:33BST
Thanks for this, John, much appreciated! So I start by going 'upstream' to source = CP104 pin2 where I get a beep (from CN13A pin4). On the way to CP102 pin2 I check all components which are supposed to be connected to this path and all is OK. Now I'm going to 'dodgy-downstream' - through the GND Jungle - or Labyrinth - to Chassis GND. Will post findings. Michael 11:35BST
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I must confess that I 'lost interest' in this repair some time ago - after nearly 600 replies and 30 pages of responses I'd respectfully suggest that the repair is beyond your capabilities as far as getting feedback from a forum is concerned.
What you really need is assistance from someone with the appropriate fault location skills but ON-SITE.
Somehow I doubt that the fault(s) is/are extensive as 30 pages of replies make them out to be and that starting from square-one would be a good thing.
I'd hate to think that what you've been doing has actually introduced problems rather than curing them!
Just a thought......
What you really need is assistance from someone with the appropriate fault location skills but ON-SITE.
Somehow I doubt that the fault(s) is/are extensive as 30 pages of replies make them out to be and that starting from square-one would be a good thing.
I'd hate to think that what you've been doing has actually introduced problems rather than curing them!
Just a thought......
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