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Post by jeremy on Jun 26, 2014 21:39:18 GMT -5
MT, I'll do that tomorrow if its okay with you, I'm just happy we located the problem board. I'll put the non working CPU board in my parts unit and test it in there, I'll have to solder some test leads to that diode to test the voltage since all the parts are on the bottom. Thanks for all the help so far, I hope we can find the problem part now.  |
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Post by jeremy on Jun 27, 2014 15:44:42 GMT -5
MT, Didn't notice that D404 was on the top, I'm re-assembling the receiver now and I'll let you know those readings
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Post by jeremy on Jun 27, 2014 16:43:24 GMT -5
Okay, checked the bad CPU board Diode D404 for voltage, one side reads 5.206vdc, the other reads 5.75vdc, I'll hack into the working one and check pin 1 on the FP connector and let you know the results
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Post by mastertech on Jun 27, 2014 16:57:53 GMT -5
Ok. This is where the 5v comes from for your standby/on button. So you have the 5v there and it then passes through R453. R453 should ohm out at 12k. Check that. If it is accessible to your probe you can see if you have +5v on both sides of it.
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Post by jeremy on Jun 28, 2014 10:03:40 GMT -5
MT sorry I didn't get back to you last night, but I was able to check the resistor, it reads 11.97k, so that seems good, and I was also able to check voltage on both sides of the resistor, both sides read +5.206vdc
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Post by mastertech on Jun 28, 2014 10:19:21 GMT -5
Hmmmm, how could it read 5v on both sides? 1 side is connected to pin 1 of CP406 where you test no voltage. Unless the trace is damaged or the solder joint is cracked on R453. Maybe do some continuity testing.
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Post by jeremy on Jun 28, 2014 10:59:55 GMT -5
I rechecked to verify, and it reads that on both sides of the resistor. Ill pull the board out and do some checking on the foils and see what I find.
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Post by mastertech on Jun 28, 2014 11:03:42 GMT -5
Pin 1 of CP406 goes directly to pin 90 of ic401. 1 side of R453 is connected directly to that line.
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Post by jeremy on Jun 28, 2014 18:04:52 GMT -5
MT, I checked continuity, and its all there perfectly. For the hell of it I rechecked the voltage on pin 1 of CP406, and now there is 5.206vdc. I swear that it wasn't there the other times I checked, but as you had said, there was voltage on both sides of the resistor, so that's why I rechecked it.
The receiver still doesn't come out of standby though.
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Post by mastertech on Jun 28, 2014 20:10:56 GMT -5
So now, when you have your test probe in pin 1 and the +5v shows, does it go to 0 when you press the standby/on button?
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Post by jeremy on Jun 29, 2014 0:40:06 GMT -5
Yes, it goes down to 2.5mv and then back up to +5.0vdc after I release the standby/on button
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Post by mastertech on Jun 29, 2014 8:24:41 GMT -5
What receiver is this board in now? Original or swapped?
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Post by jeremy on Jun 29, 2014 9:35:03 GMT -5
The board is in the "swapped" or "parts" unit. There's nothing wrong with the parts unit functionally, it was working before the board swap, it just has a severely damaged face and chassis as far as cosmetics go, making it pretty much worthless for resale.
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Post by mastertech on Jun 29, 2014 10:34:07 GMT -5
Ok, good. So we know we have the power on signal here, and we know we do not have to relay on signal, and we know the problem is surely on this CPU board.
So I would next test Q407, Q419 and D410 with DMM on diode scale.
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Post by jeremy on Jun 29, 2014 12:53:23 GMT -5
MT, Those parts must be for the DRA-697 or 297 because the solder pads/holes are there, and the numbers you gave me are, but there were never any parts installed in those areas by denon.
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