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Post by g04bloke on Nov 20, 2016 22:17:46 GMT -5
Hello again, After replacing the IC4001 (NJM78m56FA) and Q5019 (KRA103S)all the voltages are correct now. Receiver would still momentarily display power on then off again with pqls flashing.
I tracked the xvdderr line (Triggerd by voltage anomaly)to cn1405 pin 26 that is the ribbon cable to the front panel and insulated the connection as it was toggling the error on. After powering the receiver up, Power on stayed lit but no cpu boot. I quickly checked the ic's and the IC 1601 (CBX1444R) was very Hot , as in shorted. Have new one on order and will post more after I replace it.
Not the best troubleshooting technique, but sometimes it works when all else fails.
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Post by g04bloke on Nov 20, 2016 23:39:13 GMT -5
Took out IC1601 and Receiver booted and all controls work now, I am sure there is no HDMI as that was the chip I removed.It will be a test of my soldering skills putting the new one back in (80 pin smd).
Don't know if it was worth all the trouble for such an old receiver but it was more the journey then the destination I looked forward to.
Will post again when I have it finished.
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Post by leeboy22001 on Aug 3, 2017 18:02:02 GMT -5
I have the same issue on a 920k receiver, got it down to q1931, 1v8 output for digital main board, isn't outputting any volts, the gate own is there, but nothing on the output !
The PQLS light flashes, and is triggered, as mentioned before due to the XDERR flag, this is an NORing of the SMPS power good flags via diodes and transistors. HIGH ON XDERR forces the receiver to go in shutdown mode.
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Post by hwalke24 on Apr 17, 2022 16:22:08 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! Hi Guys,
Sorry to re post on this thread that's old, but I am having the exact same issue. I am extremely amateur but was following along and thought I would try this before as suggested making the 1020-K a door stop.
I have located the IC3004 but I need to know what "pull pin 70" entails? The black square (circuit) thing under IC3004 has 10,30,50,70 on each side.
Please let me know what I need to do, I have a soldering iron and a volt meter (not that i really know how to use it)
Thank you for reading!
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