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Post by tibimakai on Apr 2, 2019 18:02:48 GMT -5
OK, I will do that. Thanks
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Post by tibimakai on Apr 2, 2019 23:08:07 GMT -5
Board is purchased.
I have swapped F9888 IC(Q8921), at the 1.1VHT section from the other board and there is still no 1.1V there.
15.5V goes in, trace is cut after the L8923.
It seems like, 3.3VHT before R8903 is only 0.96V.
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Post by tibimakai on Apr 2, 2019 23:10:22 GMT -5
At the big coil there is 3.3V, that is weird.I will have to do more investigating.
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Post by tibimakai on Apr 3, 2019 22:42:31 GMT -5
I have applied 3.3V before the R8903, and than the 1.1V it was there, but still nothing has changed. So that power supply is working fine.
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Post by tibimakai on Apr 8, 2019 20:19:16 GMT -5
At this point, I believe that we should repair this missing 1.1V on this replacement 800 board, since we know that the original board did not work, with the "new" Micom IC.
FR9888 Q8921, on page #66/lower right corner.
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Post by tibimakai on Apr 9, 2019 2:08:32 GMT -5
It seems like, +3.3VTF is missing and that is causing a lot of stuff to not work.
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Post by tibimakai on Apr 9, 2019 22:07:13 GMT -5
Q8946 supplies +3.3VHT. This is the tiniest IC, that I have ever dealt with in my life. +3.3VDC is present before this IC. At this point, I would replace this IC with another one, from another board. Do you think, that is what I should do, or there is another thing that I should do, before I replace it?  |
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Post by tibimakai on Apr 9, 2019 22:17:53 GMT -5
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Post by tjmotter on Apr 10, 2019 7:00:39 GMT -5
Ouch. You can't replace from another board simply because that IC uses the smallest solderballs I have ever seen (0.25mm) and you wont find them. You can buy a new one from Mouser. www.mouser.com/_/?Keyword=TPS22924CYZPTI must warn you that these are INSANELY difficult to install. I believe they were designed for cell phones so they are tiny and they weigh almost nothing. I installed one once and it was the hardest chip I have ever installed. MUCH harder than a DSP or even a big HDMI chip. The top of these devices is reflective so it doesn't pass the heat down to the solderballs. Making matters worse, since they are so light they blow out of position with even the smallest of air flow from your heat wand. I finally got one to seat after about 4 hours of work but I destroyed one in my first attempt.... Before trying to remove this I would:
1) first use a meter to see if the device is getting the signal to turn on (pin C2 has a test point near it). If it is NOT getting the signal to turn on, I would work backwards to figure out why.
2) check EVERY device (capacitors and resistors) connected to this to see if any of them have failed or degraded. 3) check to make sure that 3.3VHT is not shorted to ground. Also check it to make sure it isn't shorted to any other voltage rails.
3) If it IS getting a signal but still not turning on AND VHT measures the same resistance to ground as another board, I would consider installing a jumper wire from Vin to Vout to see if the board turns on. If so, this IC has to be replaced but if not, there is still something else wrong. Trying to replace this IC should be your very last resort. HTH Todd |
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Post by tibimakai on Apr 10, 2019 10:15:10 GMT -5
So this is that component, that you were angry about?
Actually, I have used a tweezer from +3.3VCD and nothing happened.
The +5.0VHT is the turn on? That one is present, R8970 is 3.1K and R8900 is 3.2K in circuit, in the SM they show as 4.7k.
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Post by tjmotter on Apr 10, 2019 13:00:13 GMT -5
So this is that component, that you were angry about? Actually, I have used a tweezer from +3.3VCD and nothing happened. The +5.0VHT is the turn on? That one is present, R8970 is 3.1K and R8900 is 3.2K in circuit, in the SM they show as 4.7k. That component drove me crazy. It has no place in a Receiver so yes, this one vexes me.
I would first try to pull the two resistors off to see if they measure correctly out of circuit. Also, you will want to check the diode (D8901) as well as C8980. To test C8980 I would measure the resistance between ground and the 3.3VHT side of the capacitor to see if it is shorted.
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Post by tibimakai on Apr 14, 2019 18:59:27 GMT -5
On all three boards, the resistors show the same value. D8901 the same, though they show 1.2V one way and .228 the other. C8980 is OK as well. At the output the resistance is running upward of 3.5Kohm.
I have just noticed that most likely I have blown away a capacitor at the Q7009, C7018. So that one, is not present.
I'm a bit confused here, what to do, and which board should we continue.
Also, I have measured pin #10 at Q7009 on the 900 board and with the capacitor on the board, or without it, I measure 51 Ohm.
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Post by tjmotter on Apr 16, 2019 14:19:54 GMT -5
On the RZ900 board I would check the big Panasonic chip. I re-activated my eBay account and bought a couple of boards so that I would better understand what is going on here and I am seeing multiple instances of this chip being bad. On one of the boards (RZ820) I actually found that 4 capacitors on the bottom side of the board were BADLY fried. All were blackened and one even had a capacitor that was broken in half. After removing all of these parts I checked the resistance of the pins going to the HDMI ports and found that all were tied directly to ground.
My current position is that the second RZ800 board is going to be your best bet. If it is anything like the boards I received (NR656, R820) that Panasonic chip is going to need to be replaced. The one from your original board might still be ok since the failure stemmed from a different cause but ideally, you should replace this part with a new one (available from AliExpress). I have a broken RZ900 board coming this week and will report back what I find.
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Post by tibimakai on Apr 16, 2019 23:32:30 GMT -5
On the original board, all the voltages are there, Micom is OK, on pin #10 & 104 and the Panasonic chip is to warm in my opinion. Maybe that is the only chip, that is still bad. I will look closely for bad capacitors as well, but until now, I did not notice anything bad.
My bedroom Onkyo is OK, I had to unplug the TV and all is good.
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Post by tibimakai on Apr 17, 2019 10:50:18 GMT -5
Todd, there is a way of finding out, if the Panasonic Ic is bad?
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