Harman Kardon AVR1700 won't power up

[tom66]

Re: Harman Kardon AVR1700 won't power up

Do you still have that Rigol scope? Now would be a good time to use it.

[tibimakai]

Re: Harman Kardon AVR1700 won't power up

Yes I have it. It's collecting dust.

[tom66]

Re: Harman Kardon AVR1700 won't power up

Well, do you know how to use it? Download Audacity: http://audacity.sourceforge.net/

Plug the AVR into your computer, and generate a sine wave (Generate > Tone). 1kHz (1000 Hz) is good, generate a few minutes worth.

Set the volume on the AVR low and post a picture of what the output looks like. (Probe on RED, ground on BLACK for appropriate speaker terminals.)

For comparison, probe the working stereo channel too.

[tibimakai]

Re: Harman Kardon AVR1700 won't power up

Speakers have to be connected?

[tom66]

Re: Harman Kardon AVR1700 won't power up

Try with them connected and without. Will be useful to see if there is a significant difference.

Press AUTO on scope -- will generally give you a decent setup with most signals.

[tibimakai]

Re: Harman Kardon AVR1700 won't power up

OK, didn't notice a difference with or without speakers.
Here are the two front channels, set to 2 Channel stereo at the receiver.
The "bigger" reading is the good channel and the "lower" reading is from the bad channel.

[tom66]

Re: Harman Kardon AVR1700 won't power up

Something isn't right. Less than 10mV would not be audible. Tone should be audible, but not ear splitting...

Is that what auto gave you? Generally it's pretty good about getting you most of the way, unless the source is noisy.

Set scope to: 1V/div (VERTICAL), 500us/div (HORIZONTAL), probe on CH1, only CH1 lit up.

Also, scope has USB port for images, that may work better.

[tibimakai]

Re: Harman Kardon AVR1700 won't power up

The Auto setting showed a very small sine wave, couldn't see it.
I had to increase to the max to be able to see it properly.
It could be in the volume settings.
There are three volume settings, PC, AVR, software volume settings. Not sure which one where to set.
Scope's probe, has to be on the 1x scale and single wave?
I assume, it should measure 1000Mhz and not 100Mhz(as it measures now).
On the good channel I should be seeing a nice sine wave, am I right?
The amplitude in the software should be 0.08?

[tom66]

Re: Harman Kardon AVR1700 won't power up

1000Hz or 1kHz.
Can you hear a tone from the speakers? If you do, that is fine.
Amplitude 0.8 or 1.0 doesn't really matter.

[tibimakai]

Re: Harman Kardon AVR1700 won't power up

I can hear the tone and I have lowered it from the AVR, but at the PC side it was at 75%. From the software it was pretty low also.

[tom66]

Re: Harman Kardon AVR1700 won't power up

Show me how you've connected the probe then.

[tibimakai]

Re: Harman Kardon AVR1700 won't power up

Alligator on the black terminal and the probe on the red.

[tom66]

Re: Harman Kardon AVR1700 won't power up

Try using a bit of wire. I don't think your probe is making a good connection.

[tibimakai]

Re: Harman Kardon AVR1700 won't power up

I'm trying to measure this amp, but I don't know how to set up the scope.
I have to be on the 1X scale and 1X on the probe and AC coupling?
My scope can only save on wfm type of file and the forum doesn't accept this type of file as an attachment.

[tibimakai]

Re: Harman Kardon AVR1700 won't power up

Here are two more pictures.
The low one is the bad channel and the other is the good channel.

[tom66]

Re: Harman Kardon AVR1700 won't power up

You are just picking up noise. Please take a picture of how you have connected the scope.

[tibimakai]

Re: Harman Kardon AVR1700 won't power up

Tom, I think that I will have to test out the signal coming out of my PC first, to see if I get the right wave at the source.
I'm at work now. I have asked a colleague here about the problem I'm facing and he said that I may have a broken probe.
I'm thinking of checking out the probe if it has any damages(I haven't used it for a long time and it was just laying on the work bench, so who knows).
I could just check the signal at the RCA plug at the end of the wire, right?
Should I use the same settings at the scope, since the signal it will be much lower?

[tom66]

Re: Harman Kardon AVR1700 won't power up

If you are hearing a tone, the cable is OK. The second pic shows some evidence that the probe is working though this may be inductive pick up. The DS1052E comes with two probes so please try with the second probe to rule out the probe.

Do you have a camera to show how it is connected?

[tibimakai]

Re: Harman Kardon AVR1700 won't power up

I'm suspecting the probe's cable.

[tom66]

Re: Harman Kardon AVR1700 won't power up

Try connecting it to probe CAL (point marked _|'''|_). Then press AUTO. What do you see?