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Post by tibimakai on Aug 21, 2018 0:38:03 GMT -5
I have picked up this receiver from the bay. Previous owner stated, that had a power outage and after the power came back, the receiver was dead. I have opened up the receiver and I have checked some fuses, they all look good. There is 167V at the rectifier, also there is 11.5V VST. SMPS-POM and M_POM is 0v, though. Primary on the traf, is not open. elektrotanya has the sm. elektrotanya.com/onkyo_tx-rz800_sm_rev3.pdf/download.htmlI would appreciate any help. Tibor |
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Post by mastertech on Aug 21, 2018 11:15:39 GMT -5
Have you checked MPU Q7009 to see if it is powered?
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Post by tibimakai on Aug 21, 2018 12:36:11 GMT -5
Not yet, I have just got it last night. I will measure it later, when I get home.
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Post by tibimakai on Aug 22, 2018 0:10:27 GMT -5
It is getting some, but not enough. I'm not sure which pins should I have test, but I have tested Pins: 1, 5, 9 and 11. 1, 5 and 9 show a slowly rising voltage, from 0.38V to 0.42V. Pin #11 shows only 0.003V. When I was getting ready to put it away, I have started "feeling" for heat on the HDMI board. Very fast, I have noticed some heat, coming from under the mini HDMI female connector(front HDMI). I can't exactly find meet my finger the hottest part, but I assume that it is C7038(C106k/16V). It makes sense as well, if we look at the schematics. This capacitor, shows 3 Ohm to the ground. Tomorrow, I will remove that capacitor and I will see, if it will make a difference. What kind of capacitor is this?  |
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Post by barclay66 on Aug 22, 2018 4:13:13 GMT -5
Hi,
That should be a 10µF / 16V ceramic (MLCC) capacitor.
Kind Regards,
barclay66
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Post by tibimakai on Aug 22, 2018 10:06:19 GMT -5
It is electrolytic?
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Post by mastertech on Aug 22, 2018 10:58:34 GMT -5
Well the only thing questionable here is that it could be Q7018 getting hot which would be normal if that 3.3s line is shorted somewhere. That C7038 is real close to that Q7018 regultor. But it could be. I would not remove it yet but rather I would put some flux paste on that cap and regulator and maybe a few other parts in that area and then plug in the unit and see where the flux melts first. If it ends up the cap I would then remove it and do the ohm test across the pads. If it ends up the regulator I would not remove it just yet. Let me know what you get.
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Post by barclay66 on Aug 22, 2018 11:00:49 GMT -5
Nope. Ceramic non-polarized... |
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Post by tibimakai on Aug 22, 2018 20:58:45 GMT -5
Thanks. I hope, that the capacitor is shorted and not the MPU IC.
Mastertech is on brake again, that is why do you answer?
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Post by barclay66 on Aug 23, 2018 3:04:07 GMT -5
No. I simply saw the question, knew the answer and had the time for writing it. Just a matter of contributing factors...
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Post by mastertech on Aug 23, 2018 9:19:11 GMT -5
I am glad when others contribute. I am not always available and other opinions are a good thing.  |
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Post by tibimakai on Aug 23, 2018 18:12:52 GMT -5
I did not check the forum for two days and I did not notice, that you have posted here. I have ended up removing the VDO and the L, or ferrite bead(check picture). The short, is toward the MPU.  |
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Post by tibimakai on Aug 23, 2018 18:25:29 GMT -5
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Post by tibimakai on Aug 23, 2018 18:28:59 GMT -5
I have added a red star, where it is Q7018.  |
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Post by mastertech on Aug 23, 2018 19:37:44 GMT -5
I did not check the forum for two days and I did not notice, that you have posted here. I have ended up removing the VDO and the L, or ferrite bead(check picture). The short, is toward the MPU. You need to be more specific in what you remove other then VDO and ferrite bead. I need location id's even though you included a pic.. So I will assume you removed L7007 and you tested short to gnd on the pad towards the MPU. If correct there are still quite a few components that could be bad besides the processor. So you will have to remove parts and test the short each time you remove something. I will give you a list of parts to remove and it will be in the order I would like you to remove them and test your short each time and see if you reading drops. L7003 first. If still short then remove Q7001, then Q7020, then Q7013. Let me know what you get. !!! EDIT: I almost forgot. Can you disconnect whatever is connected to P7002A? Pin 14 on that connector is tied to that rail. |
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