Onkyo HT-R591 keeps clicking

[tibimakai]

Re: Onkyo HT-R591 keeps clicking

More pictures:

[tibimakai]

Re: Onkyo HT-R591 keeps clicking

Have you checked you're getting an output from the transformer? If the thermal fuse is blown you'll have to disassemble the transformer to get to it. To test, volts AC across one coil. For a 50V split supply amp (+/-50V) approx 35VAC should be observed across each main power coil going to the amplifier section.

I can't get a good reading. I'm just getting mV, which are dropping toward 0V.
The thermal fuse is causing this?

[budm]

Re: Onkyo HT-R591 keeps clicking

OK, so that black relay is the power relay for supplying the 120V to the primary of the main power transformer, so it is either the ucontroller is turning the relay on and off or the power supply for the relay coil is bad. You need to see the coil rating of the relay, I have a feeling you have problem in the control circuit, you are going to need the correct service manual for this thing. The only job for that relay is to supply the 120v to the transformer. You will have to force on the relay or jump the relay contact to give steady 120V ac to the transoformer, the relay is cutting in and out the 120v to the transformer.

[tibimakai]

Re: Onkyo HT-R591 keeps clicking

What is interesting, is that if I measure the two posts of the primary, I'm getting the 110V with a very slight change, like 118V and 120V.
To me, it seems like the transformer is getting the 110V, but not outputting almost(or nothing) anything.

[budm]

Re: Onkyo HT-R591 keeps clicking

Then check the resistance of the primary side. By the way the relay is clicking on and off while you are taking this AC voltage measurement?

"it seems like the transformer is getting the 110V, but not outputting almost(or nothing) anything." nothing on any of the secondary windings?

[tibimakai]

Re: Onkyo HT-R591 keeps clicking

It shows only millivolts and dropping.

[tom66]

Re: Onkyo HT-R591 keeps clicking

Yes, it sounds like the transformer has failed or the thermal fuse is bad. Hopefully it will not be buried too deep. Remember to count the turns when you undo the transformer, you must put it back exactly as it was!

[rievax_60]

Re: Onkyo HT-R591 keeps clicking

Looks like the thermal fuse is between the pin with the yellow wire and the middle pin.
On the primary side.

[tom66]

Re: Onkyo HT-R591 keeps clicking

Good eye! Could just put a fuse between there and the pin, and epoxy it to the outside case of the transformer.

[ben7]

Re: Onkyo HT-R591 keeps clicking

Looks like one of those silly 'switching' standby supplies. The relay turns to power on and off for the transformer so that the average power consumption is less .... xD

[tibimakai]

Re: Onkyo HT-R591 keeps clicking

What could cause that fuse to fail?
Can't be some other issues with the receiver?
I didn't have time to work on it yesterday. I was "playing" with my old Citizen Navihawk watch. It has a non responsive(electrically) Mode button.

[budm]

Re: Onkyo HT-R591 keeps clicking

Short circuit, over heat. You can put the lamp in place of the thermal fuse, if the transformer has shorted windings or load, the lamp (75W) will stay on bright.

[tom66]

Re: Onkyo HT-R591 keeps clicking

Sometimes a thermal fuse can be inadequately specified for that application and fail because it's too small or the transformer runs hotter than anticipated.

[budm]

Re: Onkyo HT-R591 keeps clicking

I think it may not made for High in-rush current either.

[tom66]

Re: Onkyo HT-R591 keeps clicking

Looks like one of those silly 'switching' standby supplies. The relay turns to power on and off for the transformer so that the average power consumption is less .... xD

That's not really that silly. My Yamaha 6.1 channel AVR, class AB type, pulls 38W idle (powered on no audio.) I certainly don't want that in standby mode, and I don't think many other people would either.

[newbiesat]

Re: Onkyo HT-R591 keeps clicking

Hi Tom,
How do you disassemble the transformer to fix the thermal fuse ? Any tutorial or step would be appreciate. Thank you in advance.

Have you checked you're getting an output from the transformer? If the thermal fuse is blown you'll have to disassemble the transformer to get to it. To test, volts AC across one coil. For a 50V split supply amp (+/-50V) approx 35VAC should be observed across each main power coil going to the amplifier section.

[tom66]

Re: Onkyo HT-R591 keeps clicking

Remove the outer tape insulation, unwind the appropriate coil (counting the turns), find the fuse, replace the fuse, wind the coils back exactly the same number of times and add the tape back or add new tape.

[tibimakai]

Re: Onkyo HT-R591 keeps clicking

Wow guys, so much help!
I need to pick up a couple more of these.
Thank you for all the help.
I will remove all three wires from the transformer and measure it properely when I get home.
I have made transformers when I was teenager, for two analog satellite receivers(in the 80's in Romania), so I'm familiar with them. Actually I have built those receivers from scratch, even the box, 2 meter dia. dish mount and controller for it.

[budm]

Re: Onkyo HT-R591 keeps clicking

Fyi:

[rievax_60]

Re: Onkyo HT-R591 keeps clicking

There is an easier way to remove the thermal fuse. Break away as many as it takes of the bobbin tabs to allow the fuse to be pulled upwards. In this case, breaking one should be enough, the 2nd from the right, the one with no pin.
The shinny wires belong to the fuse. Don't cut any enameled wires, they belong to the primary.
Is the thermal fuse open circuited?