Onkyo tx-nr509 power supply problem

[newbiesat]

Hello all,
I have the problem with this model in that at pin 2 and 3 on D6901 (see diagram attached) I could not get any AC voltage. All the voltage measurement included in the diagram. Any ideas?

Thank you in advance for all your help.

[budm]

Re: Onkyo tx-nr509 power supply problem

What is the ground ref. point are you using? The reason I ask is that the Emitter of Q6707, 6708 are connected to Ground, you picture is showing 5V at the Emitters, so that cannot be right, the relays are not on. Are all the boards mounting screws tight since it uses mounting holes for Ground connection to the chassis?

[newbiesat]

Re: Onkyo tx-nr509 power supply problem

Thank you BUDM. I found the crack in the board for the ground line.. that was caused 5v on the ground... Now the unit have 20Vac in and 20Vdc out at D6901.. And it have the problem when the unit turn on, it only stay for 2 seconds and shut down.. protection mode ? ... I still don't know why it's still not send 40Vac come from YEL (S1H+) and GRN (S1H-) post.

[newbiesat]

Re: Onkyo tx-nr509 power supply problem

Thank you BUDM. I found the crack in the board for the ground line.. that was caused 5v on the ground... Now the unit have 20Vac in and 20Vdc out at D6901.. And it have the problem when the unit turn on, it only stay for 2 seconds and shut down.. protection mode ? ... I still don't know why it's still not send 40Vac come from YEL (S1H+) and GRN (S1H-) post.

Here is the most recent voltage measurement (attached file).

[budm]

Re: Onkyo tx-nr509 power supply problem

So the 40V is not being switched in because Q6707 for relays RL692, 691 is off due to not getting the turn on voltage on connector pin SEC1H, You can monitor that pin to see if it changes state or not.
I do not know what kind of protection detector circuits are being used to monitor the faults. It must be monitoring the critical sections of the circuit. Does the manual show how many circuits the protection circuit is monitoring?

[newbiesat]

Re: Onkyo tx-nr509 power supply problem

There are 4 protection cc in diagram (attached). The VOLH, PROTECT_VCC, VPROTECT, and IPROTECT.

[budm]

Re: Onkyo tx-nr509 power supply problem

As you can see, there may be 4 detection lines but one detection line is fed by a bunch of OR circuits.
I.E. the VOLH is fed by 7 OR circuits (D6020~6026, D6026 fpr SBR_OUT detection), so any one the Diode'Anode goes high, it will trigger the protection circuits.
IPRO is also fed by OR transistors (Q6XXX~6011, Q6011 looks like for monitoring Front Right channel).
I cannot see the rest of the circuits, but as you can see, you will have to find out which one trips the protection circuits.
So it is not going to be easy fix. I would inspect the output circuits for any shorted circuits first.
BTW, did you check all the boards for any cracks and broken traces?

[newbiesat]

Re: Onkyo tx-nr509 power supply problem

Thanks BUDM for your quick response. I have solved the problem with this unit. All the trouble was causing by bad "IC STK443-530" that drive all the C, FL, FR Channel and FL channel was blown inside the IC when compare with the same IC.