# Onkyo NR-609 Power Cycling



## M0CRT (Oct 17, 2020)

Hi Folks

Not entirely sure what's happened but i'm now the proud owner of large brick rather than an Onkyo AV Receiver; hope someone can help.

After switching inputs last week, the receiver went 'strange' and then, without me resetting it, started to click on into standby and then instantly power off (the front display lights up with 'everything displayed' for around a second) and then powers back up again...and continues to do so; relay for the main transformer clicking away nicely.

I've removed everything and only have the PSU connected to the logic board and, with the POFF/10V/GND/12V/PWRD connected, does the same thing. Even with the fuse taken out for the main transformer...still does it.

I've attempted to trace out the power and all seems ok but do seem to see voltage on the POFF pin out of the CPU. Almost as if the CPU is 'stuck' constantly powering off.

Thermal sensor removed...same.

Any further ideas before I look at a logic board swap...in other words, could it be anything else?

Thanks

Mo


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## Alex Davidson (Jun 30, 2014)

Might pay to check the output stages. I had a similar problem a few years ago with TX-RZ810 which turned out to be caused by shorted output transistors. If I recall correctly, the logic board detects the supply voltage to the output transistors and shuts everything down if it becomes too low.


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