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Post by mastertech on Jan 20, 2016 10:21:56 GMT -5
We have not heard from guptau since his last post. So as of now there is no confirmation of a repair. It probably would be best to just go back to the beginning here and see what you find. However, if during testing you get a different result along the way, post your difference so we can see if you need to go in a different direction. Good luck.
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Post by stretch on Jan 23, 2016 15:18:24 GMT -5
I measured the output on the power supply below and was getting voltage on only the 12v line much like the original poster here. However, mine was cycling every ~1.5 seconds down to 4-5 volts momentarily, each time coinciding with some slight audible electronic noise/whine. (It's not the click of a relay.) If I unplug the 7-pin wiring harness the voltage stays stable at ~11.8 volts. Where should I go from here? I'm assuming this means a protection circuit is being tripped. It's posted earlier in this thread, but here's the schematic for the power supply. 
The board that wiring harness connects to is considerably more complex:  |
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Post by mastertech on Jan 23, 2016 18:07:21 GMT -5
Sounds like something is shorted some where pulling the voltage down. Plug that harness back in and then go to the HDMI board and look for a 5 pin connector(JL2100B), disconnect it and then test your 12v supply again and see if it is now steady 12v.
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Post by stretch on Jan 23, 2016 22:14:43 GMT -5
Thank you for the reply. I disconnected the 5-pin JL2100B and got steady 12v. What's next?
It's probably irrelevant, but my HDMI board was replaced by Onkyo warranty service about two years ago. My DTS chip says "new" on it.
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Post by mastertech on Jan 24, 2016 13:27:17 GMT -5
Plug that harness back in and re verify the 12v drops again. If it does then is looks like you are going to have to remove some parts until the voltage becomes steady.
Are you able to unsolder and remove small surface mount parts?
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Post by stretch on Jan 26, 2016 21:31:57 GMT -5
I plugged the harness back in and the 12v signal is no longer dropping. I'm assuming this means I've left something unplugged somewhere- something had to have changed, but I don't immediately see what.
As far as soldering things, it probably depends on the size of what I'm soldering. I've got a basic soldering iron but haven't used it much since assembling an R/C car and some speaker crossovers (all heavy-gauge wire) as a young teenager. I'm not adverse to practice but this seems like the wrong thing to practice on. I'll defer to you as to how easy or difficult a particular task would be.
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Post by mastertech on Jan 27, 2016 11:43:17 GMT -5
I would suggest that this is probably a bit more then you can handle. You could experiment on it and learn how to read schematics well. Always concentrate on testing and verifying correct voltages.
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nir
New Member
Posts: 10 
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Post by nir on Oct 4, 2016 14:59:36 GMT -5
Hi, i also having the same problem as stretch described. My onkyo tx-nr717 will not power on at all. Like stretch describe the stby 12v is cycling every 1-2 seconds. It drops to 6v. I also tested the mpower on the cpu board and it is cycling from 3.3 to 0. Because of that there isn't stable Vmpu of 3.3v.
My question is does that mean that the cpu board U0091 (main cpu q7022) it faulty. Or there is shorted some where pulling the voltage down?
And how can i find that?
Thanks
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Post by mastertech on Oct 4, 2016 19:09:49 GMT -5
Hello nir and welcome. At this point we cannot assume anything. But we can most likely narrow it down and find out.
Did you try disconnecting the 7 pin plug on the power supply and test pin 3 to see if the 12 volt is now stable?
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nir
New Member
Posts: 10
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Post by nir on Oct 5, 2016 14:53:34 GMT -5
Hello and Thanks. yes i did disconnected the 7 pin plug and pin 3 shows 12v stable.
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Post by mastertech on Oct 5, 2016 15:30:13 GMT -5
Ok, reconnect that harness and locate the 5 pin harness from the video board to the HDMI board (JL2100A) and disconnect it and see if the 12v is stable. If it is then reconnect that harness and recheck the 12v and see if it goes back to fluctuating.
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nir
New Member
Posts: 10
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Post by nir on Oct 5, 2016 17:45:48 GMT -5
Ok i did what you ask me to do. The 12v was stable. And after I connected the harness and rechecked the 12v stayed stable!!
Now what i am getting is 12v on pin 3 stable and on pin 7 when i push the power button the voltage goes to 3v so long it is pushed.
I think that the relay do not function well. The device still not power on.
What do from here?
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Post by mastertech on Oct 5, 2016 21:49:38 GMT -5
On the power supply board locate R9104 and see if you have 12v on both sides.
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nir
New Member
Posts: 10
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Post by nir on Oct 6, 2016 1:48:29 GMT -5
Yes there's 12v on both sides of the R9104. To be more accurate 11.8v. This also the reading that i get on pin 3. The power drops from 12v to 11.8v in the diode D9008 on the power supply. In the anode side i get 12v and on the cathode i get 11.8v. Is this ok?
And where to go from here?
Thanks
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Post by mastertech on Oct 6, 2016 10:26:45 GMT -5
The relay on the power supply is not clicking when you push the power button? Sometimes they are not very loud. If it is not clicking then I would remove the relay and test it with a 9 volt battery. Just connect the battery to the 2 pins or the relay that were marked 2 and 3 on the board and the relay should engage. If it does engage you can connect your meter to the other 2 pins of the relay and set your meter to continuity or diode mode and it should read short when engaged with the battery.
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