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Post by mastertech on Jul 5, 2014 12:20:46 GMT -5
No video required. Testing with removed boards can sometimes give false readings. I only recommend that if I have looked over all circuits and verify it is acceptable.
Lets try this. Remove Q4944 and C4941, reassemble and try powering up again.
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Post by cguy123 on Jul 5, 2014 14:53:52 GMT -5
OK. I've removed both components. That capacitor was so tiny, I could barely see it. I'm certain I won't be able to solder it back in again without a replacement. I've never removed a component like that before.
Anyway. As soon as I plugged it in, the mcacc light started flashing, just like before. So I did a 'hard' reset, holding the tune down and on/off button and the unit displayed 'power on' like before when I did this procedure, except this time, it didn't shut itself off again. It stayed on and just had 'power on' on the display. Nothing else seemed to be functioning, but it did stay powered up.
When next? I hope this is progress, this is very tedious work! lol...
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Post by mastertech on Jul 5, 2014 16:41:25 GMT -5
Yes, this is progress.
We will need your eyes now to see how we can do the next test. I do not know if the next connection has a harness or direct connect but it goes from the main board(same board you are on) JP4001 to the audio board(the one with all the audio inputs on it) CN2107. Some how we need to test for some voltage on 1 of these connectors with it powered up. On CN2107 pin 3 is gnd. Then test pins 1 and 6 for voltage. Probably need fly wires if nothing is accessible.
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Post by AB CD on Jul 18, 2014 23:09:40 GMT -5
Have the same problem and cheering you guys on. Thx for posting. PQLS light flashing
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Post by jeremy on Aug 12, 2015 8:31:13 GMT -5
MT, Was wondering if you have any ideas on why the VSX-1020 shuts down and PQLS is flashing at random? I ask because I still have one of these and the thread just seemed to die off, lol. Mine not only does the PQLS shutdown, but it will power off then on instantly and the relay clicks on & off very fast.
When it does work it works just fine...
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Post by mastertech on Aug 12, 2015 22:34:55 GMT -5
Well it kinda sounds like a bad connection or solder joint. I have had some Pioneers where some of the connectors pins solder joints were ringed. Even on the digital board in non heat related areas.
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Post by jeremy on Aug 13, 2015 7:51:43 GMT -5
I suspected bad connection/solder issues somewhere in the receiver myself. So far between the 2 I have I have found out that: Unit A: - Works for any random length of time (minutes to over an hour or 2) before it will shut down or come back on, or the relay starts clicking like crazy and the receiver freeze - No other issue seems to occur with this AVR other than above. - Tried both Unit A and Unit B HDMI ASSY board (the digital main bd) in this AVR, both seem to behave the same, except with Unit B HDMI Assy, the digital display glitches when it shuts down/powers back on once in a while, Unit A HDMI Digital Assy does not appear to have that issue, otherwise both seem fine so I don't think the HDMI boards are at fault. -Suspect the issue is on the Main(mother)board of the AVR where the speaker terminals & PSU are, since the power on off problem stayed consistent on this AVR regardless of all other boards being swapped. Unit B: -Would not even power up, as dead as it gets - found out the faceplate board is fried (did not get too into what specific part is bad) due to the ribbon cable at the HDMI ASSY end being damaged and shorting itself out -Used good faceplate from Unit A and the receiver relay clicks but nothing else happens. -Suspect the issue is the mainboard of the AVR because this receiver issue stayed consistent as well (would not power on other than hearing the main relay click on, had to unplug AVR to hear it click off, no display on the faceplate) So my next step I guess would be tearing out the mainboard on one of them and seeing whats going on. I wouldn't mind getting one of these going for the garage. I'm surprised to see they are holding a pretty good value of $150-$200+ for being and older AVR. If you think there's anything I should try I'm all ears  |
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Post by jeremy on Aug 13, 2015 12:58:18 GMT -5
Ok here's a bit of an update. I pulled the mainboard and recapped the entire board except for the big 6800uf, the little 6800uf, the 3300uf, and the 2 4700uf capacitors. I also redid a few hundred solder connections on the mainboard too. None of that really seemed to make a difference, but I noticed the amplifier getting warm without any speakers on it. A minute or 2 later, the 330uf 63v capacitor burst. I put too low of wattage one in place of the 63v, (I put a 25v in there). So my error caused me another 30 minutes of work replacing that capacitor with the correct value. I got it all working again, but it still powered on and off randomly. The one board I didn't try anything with was the audio input board (all the Red/white RCA jacks). I unplugged that one from the mainboard and the receiver hasn't glitched at bit. (so far  ) So my next step is to try the one from the other 1020 and see if it does the same thing. Hoping it won't, but wouldn't be surprised if it did. I would suspect that a component on the mainboard is being dragged down by something on the audio input board, or unlikely (but not impossible) the 2nd audio input board is also bad. No guarantees yet, I want to let the AVR sit on all day and see if it turns off by itself. I think if it gets past 24 hours I'll be fine, I haven't been able to use it for more than an hour, 20 minutes is the average it kicked out after power on. Will post back more when I find anything new |
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Post by jeremy on Aug 19, 2015 11:04:38 GMT -5
MT, got a bit of a rough spot I need help getting out of... lol
When I plug CNT4 from the mainboard to the amp, the receiver shuts down into protection and wont come out until I unplug that connector, and do the reset for it. Then the AVR works fine.
CNT4 appears to be B+ and B- going to the amplifier. Now this only started happening after I put a 25v 330uf capacitor in place of the 63v 330uf capacitor on the mainboard and the 25v burst. I realized my mistake and put the correct cap in and everything is fine except when I plug that connector in.
Also it's not possible for me to check voltages while assembled, if that helps.
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Post by jeremy on Aug 19, 2015 16:19:14 GMT -5
Okay, I got myself out of that situation. The amplifier is what I damaged, just one transistor is all it was so that's fixed and good to go again.
A little more info on the random power on/off thing. I checked out the service manual to see what the PQLS error meant, which according to the SM it means when it blinks after a shutdown that means voltage anomalies were detected for the Digital Main Board. Pin 70 on IC3004 is for that detection. Since the AVR appears to operate normally other than that random power on/off issue I decided to pull pin 70 from the circuit.
The AVR hasn't had a problem since I did that. Not one hiccup or random on/off or anything other than just working. So I have concluded that IC3004 is a cheap P.O.S. and for the time being have decided to leave pin 70 disconnected. If the AVR glitches again, I'll post back with more info. For now it seems I have it working!
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Post by jeremy on Aug 20, 2015 8:25:06 GMT -5
Just wanted to update and let everyone know the 1020 is still working perfect since lifting pin 70 from IC3004, been operating it in various conditions such as loud volume, no volume, powered off over night, letting it run for a few hours straight, different inputs, etc... so far all is well |
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Post by mastertech on Aug 20, 2015 9:27:57 GMT -5
Good job. Are you going to just leave it that way or try to resolve it?
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Post by jeremy on Aug 20, 2015 21:35:39 GMT -5
Good job. Are you going to just leave it that way or try to resolve it? Since the AVR seems fully functional and no other protection circuits are kicking in I'm probably just going to leave it, the AVR is still working perfect as of 9:33PM CST so my bet is either IC3004 programming is faulty and the detection is just too sensitive, or the IC itself has a fault. I'm doubting the AVR itself is having an issue since all the functions are working as expected.
I have another one of these that I used to get this one diagnosed. It has a power issue on the mainboard (powers on, 1 relay click, no display on the front panel, wont power off with the button, have to unplug it), but otherwise that one should work once I replace the faceplate mainboard (when one appears )
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Post by g04bloke on Nov 13, 2016 19:27:05 GMT -5
I know this is kind of old but I just bought a non working vsx-1020k with blinking PQLS light. After some T.S. I have found IC4001 (NJM78m56FA) and Q5019 (KRA103S) defective.I don't know why but IC4001 was passing 12v instead of regulating the voltage at 5.6, Q5019 has an open base. While either one of these would have been enough by their self to cause a shutdown both being bad at the same time have made T.S. interesting. I am currently waiting for the Q5019 replacement and will keep you advised of the results. Hopefully this is of some assistance to all of you with similar issues.
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Post by mastertech on Nov 13, 2016 20:15:33 GMT -5
Good to hear. Yes, keep us updated. And welcome to the forum. |
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