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Post by pleiades on Feb 15, 2019 12:36:19 GMT -5
First Hello and thank you for any help!
I recently bought a Onkyo TX-NR616 for about $60 problem beeing that is completely dead no power and no lights.
Took it apart and the power supply is good i get the right voltages plus the relay latches if i jump powerd and gnd but still dead. I am a novice in electronics and measuring with the DMM at various points on the board from the schematics problems that i see are the 3.3v rail that goes from q7018 also q7019 the 5.6v regulator gets hot very hot so i measured the input of the 3.3v regulator and the output ...input is normal 5.6v output is i think partialy shorted to ground because i get 1.09v from the regulator to anywhere i measure on the rail including pin 1 of the q7009. I measured from common ground to the power button same 1.09 if i press it drops to 0 and on release back to 1.09. I tried taking off the 3.3v reg. surrounding caps and the regulator itself but still the short remains i tried measuring a lot of points on the 3.3v rail but fail to discover the short...my suspicion is the q7009 is dead...if anyone can help. Thanks.
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Post by mastertech on Feb 16, 2019 19:43:07 GMT -5
Your conclusion looks like it could be valid. To confirm you would have to remove either Q7009 or all other components on that rail unless it is a high resistance line. A high resistance line would not likely pull down that rail.
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Post by pleiades on Feb 23, 2019 9:42:16 GMT -5
Thanks for taking your time answering me. Lifting pin 1 (AVREF0) of q7009 brings back my 3.3v rail and the reciever powers on briefly for about 1s and all the relays latch and remain like that... the display shows volume then nothing and lights out...continuing my hunt checking what goes from pin 1.
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Post by tjmotter on Feb 23, 2019 10:09:51 GMT -5
I think your issue may lie elsewhere. Q7009 is the Main Micom. It is responsible for all diagnostics as well as the front display. If you are getting "Volume" on the front display, it would indicate (to me) that the Micom is working. Understand that the Micom is the device that turns power on to EVERYTHING else in the system so if it wasn't working, the relay's wouldn't latch and the front panel would be dead.
I would first check the following diodes: D7003, D7002. These are designed to protect the MICOM in the event of over voltage or current.
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Post by pleiades on Feb 23, 2019 10:20:10 GMT -5
both show 799 on diod mode. The MICOM is working only with pin 1 desoldered and lifted
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Post by tjmotter on Feb 23, 2019 10:35:53 GMT -5
You will have to hope that the issue lies anywhere other than Q7009. The Main Micom chip has embedded flash and Onkyo adds code to this flash so you can't simply replace the chip. I have replaced MICOM's several times and it requires:
a) having a copy of the code (and the signature) - this can be pulled from a working system
b) a programmer that can work with this - Digikey used to offer the Renesas E1 programmer but I was recently notified that it is being discontinued
c) a new chip - Renesas will not sell these chips. I have tried to buy them through Digikey and Mouser and both told me that Renesas refused the order. The only way to get them is to pull one off a different board.
HTH
Todd
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Post by pleiades on Feb 23, 2019 10:41:22 GMT -5
can i replace it with one from say like a 646 or 414? without flashing? Thanks
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Post by tjmotter on Feb 23, 2019 10:54:39 GMT -5
can i replace it with one from say like a 646 or 414? without flashing? Thanks You are going to have to flash it but if you use a chip from a different model you may be able to get enough functionality to be able to use the standard Onkyo Firmware update. This may work but it may not. Of the two, I would suspect that the 414 is a closer match. |
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Post by tibimakai on Feb 25, 2019 11:31:09 GMT -5
Todd, sorry to be off topic, but Maybe I should try this trick on my 800? Maybe using a 656 Micom? I don't know, to which generation belongs this RZ800? 4 series(646), or 5 series(656)?
Since we have tried the 838 Micom, maybe we should try a newer one?
That is an option, to make it work partially and do the upgrade after that? That is an interesting new development, that I did not thought about.
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Post by tjmotter on Feb 26, 2019 8:19:49 GMT -5
I fear that the only option is to find an RZ based system. The "trick" I outlined above is exactly the same as what we have already tried on your RZ. I am hopeful that once you get the "smoking" issue fixed you might be able to get enough functionality working to allow you to perform the firmware update. BTW, did you ever go back and double check each of the pins on the MICOM to make sure none of them are bridged (or disconnected)?
A year and a half ago (before I bought my MICOM programmer), I found a guy on eBay who had a damaged RZ810. He wanted $250 for it which was more than I wanted to spend but it was a simple blown channel so I thought I could fix it. I reached out to him and offered to buy the receiver, fix it and then return it to him. The eBay process made this pretty easy and it even gave me a HUGE discount on the return shipping. It was an easy fix but what I learned was that the RZ had a VERY different firmware load. The diagnostics are 10 steps ahead of what an NR can do and even some of button combinations to start diags were different. I fear that all NR firmware is going to be far different than the RZ firmware regardless of generation. For example, did you know that the RZ will first apply ~30V to the main amplifier circuit to perform its diagnostic checks? Only when the receiver passes the tests does it apply the full 65 volts to the amp circuit. I had never seen that before and I sure haven't seen it on any NR systems.
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Post by tibimakai on Feb 26, 2019 11:33:00 GMT -5
I didn't know.
So, most likely, the 838 Micom won't work then with thes RZ, right?
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Post by tjmotter on Feb 26, 2019 14:15:05 GMT -5
I didn't know. So, most likely, the 838 Micom won't work then with thes RZ, right? The hope was that it work well enough to allow the system to boot so that you could use the Onkyo Flash upgrade utility to get it back to the correct levels for an RZ. All you really need it to do is to allow the system to start up, enable the front panel buttons and initialize the USB port... The USB port is tied off of the DSP so if the MAIN MICOM could get far enough to allow the DSP to start and then provide enough functionality on the front panel, it could work. If not, I don't see how any NR code would work, you would need to get RZ code. |
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