Onkyo TX-NR809

[nataf10]

Hello friends.
I have a ONKYO TX-NR809 Home Thea' .
The unit go to protection mode immediately when I power the unit.The relay click can be heard and the fluorescent display lit for a second and then power go back to Stby mode.
I checked all the output power transistors for any short circuit but all looks good,tried to disconnect other board to get the power turn on but NOTHING!
Any idea/solution will be welcome.
Thanks in advance

[ben7]

Re: Onkyo TX-NR809

Control circuits might have a short?

BTW, the amp could have an open-circuit resistor. That might cause there to be DC on the speaker output. That would put the amp into protection right away...

[budm]

Re: Onkyo TX-NR809

Check to see if it has more than 2vdc on the speaker relay contacts (the DC sensing for speaker protection is set to detect anything more than 2VDC).

[nataf10]

Re: Onkyo TX-NR809

Hi there,
I checked the DC Voltage on the speakers output and find no DC Voltage.
Do you have another tip?
Thanks!

[ben7]

Re: Onkyo TX-NR809

Hi there,
I checked the DC Voltage on the speakers output and find no DC Voltage.
Do you have another tip?
Thanks!

Have you checked for shorts on the output of voltage regulators? Might just be a short, or failed voltage regulator.

Pic would help us point out where to check things

-Ben

[budm]

Re: Onkyo TX-NR809

You need to check the DC at the relay input contacts (fed by the amplifier output), not at the speaker terminals since the relay is not activated.

[ben7]

Re: Onkyo TX-NR809

You need to check the DC at the relay input contacts (fed by the amplifier output), not at the speaker terminals since the relay is not activated.

That's true!

I've seen some amps that short the speaker outputs when the relay is off. (so there is no chance of shorting the amplifier)