VSX-925-K flashing PQLS light, turns off immediately
Hello,
I could not find the Pioneer VSX-925-K receiver in the device list.
The PQLS light flashes when the unit is turned off, and if I press the power button to turn it on, it turns back off by itself after about a second.
I have found the service manual for the VSX-1020-K which according to some info I’ve found is very similar to the 925. It says in the “error indications” section that a flashing PQLS light means “"Abnormality DC voltage of the Digital power supply" detection”.
In the “diagnosis flowchart” section, I have done the “Step 2: Power supply” flowchart steps. All voltages the flowchart had me check were OK.
Where do I go from there? Are there more checks I can do to diagnose the specific problem, and possibly repair it? I have a multimeter, a soldering iron and some experience soldering, so I should be able to repair the problem if I knew what it was. I also have an oscilloscope (compact 1-channel one) but no experience actually using it, so if I need to use that to go further I’d need a bit more hand-holding.
Thanks in advance,
J-S
Here are pictures of the unit:
The Digital Main Assy board (with the HDMI ports, at the top):
The Main Assy (power board, at the bottom):
The main transformer:
Service Manual for VSX-1020 which is very similar to VSX-925, and the manual is much more detailed than the one for the 925:
CP11 in the service manual
CP11 in my unit
O/L Detect wire disconnected
Edit 2021-12-21
Area around X361
Area around X362
Wear around screw holes
Edit 2021-12-24
Cold solder joints on HDMI ports
Esta é uma boa pergunta?
@skylark13 you have tried a reset? Remember that the flashing PQLS indicates DC voltage on a speaker output line. Most commonly caused by failed transistors. Have you checked for obviously damaged components like failed capacitors, burnt MOSFETS etc?
por oldturkey03
Thanks for your reply @oldturkey03 .
I do not know how to do a reset on this unit. I can't find the info in the service manual I have. Do you know how to do it?
I have checked all the capacitors, none are bulging or leaking. I don't know what a MOSFET is, what does it look like?
Thanks again!
por Jean-Sébastien Guay
@skylark13 should be something like press and hold the "Multi-Zone On/Off" and the "Tune Down" (or Preset Down) buttons for about 4-5 seconds and see if it power on. Post some good pictures of your boards with your QUESTION. That way we can check for any obvious damage.
Adicionar imagens a uma pergunta já existente
por oldturkey03
@oldturkey03 I have tried holding Multi-Zone On/Off with either Tune Down or Preset Down for over 10 seconds, and nothing happens. Note that I do this with the receiver turned off, because it does not stay on long enough for me to be able to do it when it's on...
I have edited my initial post with pictures of the boards where I think the problem should be (hopefully they're good enough). If there's another board you'd like a picture of, just let me know. There are 2 fuses on the bottom board (the brown one), I have tested them and they are both good.
Thanks!
por Jean-Sébastien Guay
@skylark13 boards look ok with nothing really obvious but hard to make out since the boards are mounted. CP11 would be of interest. Check the schematic and see if you can determine that pathway and check those components. I suspect a bad power transistor.
por oldturkey03
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