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Post by tibimakai on Sept 5, 2018 22:39:17 GMT -5
C700 it was OK as well, still measured 3 Ohm, after I have removed it.
I ended up removing Q7009, and now I measure 197 Ohm.
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Post by mastertech on Sept 6, 2018 16:04:06 GMT -5
What a shame. I am not seeing any availability.
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Post by tibimakai on Sept 6, 2018 17:40:54 GMT -5
I'm thinking, it would be possible to get another IC from another Onkyo unit(different model), that uses the same IC?
For example, there are some broken HDMI boards on Ebay, that are $15+ $3 shipping. Maybe, a TX-NR646 board.
Hopefully, after it would boot up, I could reflash the receiver, with it's proper firmware.
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Post by mastertech on Sept 6, 2018 17:56:17 GMT -5
Interesting. I looked up the nr646 ic part number and it is exactly the same as this rz800. And I dont mean the number on the ic itself but the actual Onkyo part number. This would indicate to me they are the same part, firmware and all. So I would think this would work, at least the nr646 anyways.
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Post by tibimakai on Sept 6, 2018 22:03:34 GMT -5
There are many Onkyos, that use the same IC. Even base and old models, like 414, 616, etc.
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Post by tibimakai on Sept 11, 2018 0:12:52 GMT -5
I'm working on this, but I don't have a result yet.
Picked up an Onkyo TX-NR717, for $45.
I have almost felt like, I have screwed myself, because this IC wasn't on the HDMI board.
Later I have realized, that it was on a separate vertical board.
I have made a mistake, using the Quick Chip low temp solder.
It was a nightmare, to clean all the pins. I have bent most of them.
Today, I have managed to solder almost all the pins, but I still have to go over each pin, to make sure, that none of the pins are loose.
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Post by tibimakai on Sept 13, 2018 0:09:52 GMT -5
Man, I'm having a very hard time soldering this Q7009.
Somehow is done, but I still not feel 100% sure, that all the pins are soldered properly.
I have tried starting it, but initially nothing happened.
After a couple of power ups, eventually I have heard the relay click and both fans spin up, but after a couple of seconds it turned off.
Nothing on the display.
I have still felt that area to be warm, where the two VDOs are. It was too late, to do any measurements.
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Post by tibimakai on Sept 13, 2018 22:48:01 GMT -5
I had a few minutes today, to check on this receiver, 3.3V it is OK now.
What I have noticed, that +1.1V VHT seems shorted, 0.43 Ohm only and I measure 0.56V(L8922). +1V DSP, shows 24.3 Ohm and 0V(L8932).
Quite a few components get hot.
5.2VDC is OK, 3.3VHT is OK, 1.8VHT is OK as well. There are five big coils (see picture with the top view), that are clearly marked, with these voltages.
Left five coils, are the once that are OK. The two on the right side, have issues.
See page #66.
Most likely this is the reason, that shuts down in a few seconds, because there is a short on the HDMI board.
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Post by tibimakai on Sept 13, 2018 22:54:44 GMT -5
I know this is a guess, but can't be the HDMI Ics that could be shorted, since this is a power outage victim?
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Post by tibimakai on Sept 15, 2018 16:30:45 GMT -5
I have cut the traces, at +1.1VHT TP885 and at +1.0VDSP TP884(those capacitors, near these test points are not on the board)(Page #66). 1.1V is there, but something is shorted after that, Q8000, or Q8401. That short, is pulling down the voltage. I have inspected visually the parts around these two ICs, but I did not see anything bad.
The 1.0VDSP, is not there, because it is supplied by the 3.3VDSP source - Q8967, which delivers only 1.5V. It looks like, this is shorted as well.
I'm still suspecting, one of the HDMI ICs, is most likely shorted.
I would like to hear what you have to say, before I would take another step.
If it would be me, I would start removing these ICs. One of them, has 216 pins. Sounds scary.
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Post by mastertech on Sept 15, 2018 18:54:57 GMT -5
Well with having a quick look at those HDMI ic's and your 1.1VHT voltage short it could be one of those 2 ic's. But rather then remove 1 or both of those ic's I would remove inductors on those feed lines instead. At least then if 1 or both ics check out ok you did not have to deal with soldering all those legs. Plus they have thermal pads which can be very difficult to deal with. Looks like quite a lot of inductors but easier then removing those ic's. I did not look over that 1.0V DSP circuit. One thing at a time.
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Post by tibimakai on Sept 16, 2018 13:48:15 GMT -5
If I unplug P7000 ribbon cable, the protection mode is disabled, so it won't shut down and bad components will start heating up.
This is the way, how I have noticed, that Q8000 IC is getting hot.
I will give it a try removing it.
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Post by tibimakai on Sept 17, 2018 17:46:43 GMT -5
I have removed it, but did not change much, except, that 1.1VHT is OK now.
3.3VDSP is still not OK.
Now, if I leave P7000 unplugged, I start smelling burnt smell.
I don't know, what it is yet, but I have noticed that the heatsink at Q9202/Q9203 is warm.
Removed preamp section and I have tested the final transistors just in case, but finals are all good. The smell, is not coming from the amp section.
It seems like the burnt smell it may come from the baseboard, or from one of the boards, under the HDMI board. This receiver, is way more complicated, then a let's say, TX-NR646.
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Post by tibimakai on Sept 17, 2018 18:13:26 GMT -5
Looking at page #66 at Q8967, there is a 3.3V input from 3.3VDC, but there is no output at pin #1. This supply, supplies Q8931 for the 1.0VDSP. Most likely this is the reason, I'm not getting the 1.0VDSP.
I have also measured the output of Q8967, for short, but there is no short. I think, that this vdo is bad. It is causing 3.3VDS and 1.0VDS, to be missing.
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Post by mastertech on Sept 17, 2018 18:34:59 GMT -5
Q8967 does not supply Q8931, it turns it on. So Q8967 has 3.3VDC in but does not have 3.3VDSP out. But is Q8967 being turned on by pin 4 (M2_PON)? Probably not if the receiver is not turning on. You are chasing nothing here.
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