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Post by dolivas27 on Aug 18, 2015 23:05:22 GMT -5
Pulsing is still gone so I installed it back in the receiver now when I press the power button I here the relay click on then off I never get the standby light or and display?
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Post by mastertech on Aug 18, 2015 23:36:18 GMT -5
Guess it wants to be stubborn. Sounds like the shutdown would be going into protect. Have you had a 636 with a bad amp that shutdown like this?
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Post by dolivas27 on Aug 18, 2015 23:54:00 GMT -5
Yes I have fixed many of the 636's but I checked the amp section and it looks fine the weird thing is I never see the standby light on the front and never see any display.
should I have a steady voltage on R7035? when I press the power button it jumps to 3.0v and then right back down.
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Post by mastertech on Aug 19, 2015 0:23:42 GMT -5
R7035 feeds pin 1 which is a control line and I would expect that voltage to respond like you say. This is how the processor turns the eeprom on to receive or send data. CS means chip select. The eeprom main pwr line is on pin 8 and that line should hold steady at 3.3v regardless of any selection changes.
I will look over stuff tomorrow to see how to proceed next.
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Post by dolivas27 on Aug 19, 2015 0:29:16 GMT -5
Ok thanks for all the help
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Post by mastertech on Aug 20, 2015 10:02:00 GMT -5
Ok, I'm back.
I need the DC voltage readings at pins 129 and 130 of Q7009. You may have to monitor the pin while you power it up and see if it is the same when the relay latches on and then goes off. Let me know what you get.
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Post by dolivas27 on Aug 20, 2015 16:14:09 GMT -5
Ok I received in another 636 receiver today with a blown channel.
I removed the main board from it and installed it in the unit we have been working on and guess what the relay is now clicking again like when we first started.
So I sniped the leads to the bad channel on the new receiver and reinstall the board to test it and all is good.
So I install the main board we have been working on in the new receiver with the blown channel and it works fine. I decided to update the firmware on the board as it was really old.
I did the upgrade via USB just to make sure the USB was working on the main board and everything went perfect. So I tested all the HDMI inputs and I would say the main board is working just fine.
I am upgrading the main board on the unit that just came in right now and once it is done I will reinstall the original main board in the receiver we have been working on.
Oh one thing I noticed is the the main board that just came in is a revision A board and there are some factory jumpers on the under side of the board I will take some pictures for future reference. I would say it looks like there was a problem with the revision A boards that was fixed at the factory.
My plan now is to reinstall the original updated main board that we have been working on in the receiver and then try to replace the power supply with the receiver that I knows works.
What's your thoughts on this?
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Post by mastertech on Aug 20, 2015 16:33:09 GMT -5
Well if you want just a guess then I cannot give you one as the current issue could be caused by anyone of a few boards. But when I asked you to check the voltage on those 2 pins on Q7009 I was not thinking there was a problem with that board anyways. It is just the most logical place to look to see if it is a protection shutdown problem. But it was good for you to verify the main board is functioning properly.
And if you want to try to narrow down to the problem board by changing boards then that is ok with me. Saves time.
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Post by dolivas27 on Aug 20, 2015 16:37:04 GMT -5
Well do you think changing out the power supply is a waste of time?
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Post by dolivas27 on Aug 20, 2015 16:53:18 GMT -5
Ok I checked to pins for you an here is what I have
Pin 129 = .580v
Pin 130 = 11.39
They stay the same when the power button is pushed.
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Post by mastertech on Aug 20, 2015 17:51:02 GMT -5
This Onkyo protect circuit is a little over elaborate but it looks like they should both be low.
Can you verify these 2 pins in the working receiver?
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Post by dolivas27 on Aug 20, 2015 18:19:05 GMT -5
Yes you're correct on the working unit both the pins are low.
Pin 129 = .518
Pin 130 = .518
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Post by mastertech on Aug 20, 2015 18:50:32 GMT -5
Ok, yeah,it is going into protect.So first we need it to stay on to find out where the problem is. On the amp board, locate R6451, remove it and see if the receiver now turns on and stays on.
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Post by dolivas27 on Aug 20, 2015 19:37:06 GMT -5
Ok give me a few to get that one removed I have to disassemble the whole receiver.
Is there anything in that area that I should be looking at while I have it apart?
If is does not power on at that point whats the next step as it might be late before I can get it removed.
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Post by mastertech on Aug 20, 2015 20:40:32 GMT -5
If it still does not stay on you can try removing R6454. Should be in the same area as R6451. If it still does not stay on then there must be some slight voltage on a speaker output line. I do not know how accessible test points are but if pin 9 (NF*)of each channel connector (page 30 in manual) is testable then you can check each one for any DC voltage to try to narrow it down. Once you find the channel with some DC, even if small you can then remove the diode or resistor on the HVOL line of that channel and see if it stays powered on.
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