Harman Kardon AVR1700 won't power up

[tibimakai]

Re: Harman Kardon AVR1700 won't power up

You are right, it can't be the probe, because the square wave is there when I test it.

[tom66]

Re: Harman Kardon AVR1700 won't power up

So until I see how you have connected it I cannot advise further.

[tibimakai]

Re: Harman Kardon AVR1700 won't power up

OK, here it is.
I have measured the RCA end of the audio cable and I'm getting the same reading. Like an overlapped sine wave.

[tom66]

Re: Harman Kardon AVR1700 won't power up

I don't think that connection is reliable enough. Can you try with a piece of wire connected to the screw terminal and the hook probe connected to the other end of the wire?

[tibimakai]

Re: Harman Kardon AVR1700 won't power up

I have just tried at work the same setup and it shows a nice sine wave.
I have to check out again my home setup, what is wrong there.
Yesterday, I have measured some of the transistors, basically comparing the ,measurements between channels and I have noticed some discrepancies.
I guess I still have some bad component there.
At of the A1360Y at he collector I have 0V and at the other channel, I have 1.1xxV.

[tom66]

Re: Harman Kardon AVR1700 won't power up

Basically we need to get a view of how the waveform is distorted so we can figure out where the problem may be.

[tibimakai]

Re: Harman Kardon AVR1700 won't power up

OK, after fiddling with the scope for a while(I don't know why I have to play with it?), I have managed to see a sine wave.
I don't have the option to save it in Bit file, only wfm and I can't attach those type of files here.
I'll have to take pictures.

[tibimakai]

Re: Harman Kardon AVR1700 won't power up

I'm trying to add some links from Dropbox for the two files.
https://www.dropbox.com/s/bf43rpmfgtc5ol8/NewFile0.wfm
https://www.dropbox.com/s/t2rer0d8sg7y05y/NewFile1.wfm

I have installed the scope's software, but it takes some time until I will figure it out how to use it.

[tom66]

Re: Harman Kardon AVR1700 won't power up

You need to select BMP format (Storage Button > Storage > Bit map) then press External to save. The WFM file is just raw data (X,Y coordinates to plot.) BMP is exactly what is on LCD.

[tibimakai]

Re: Harman Kardon AVR1700 won't power up

Unfortunately, I don't have that option. I have: Storage, External, New file and Save.

[tibimakai]

Re: Harman Kardon AVR1700 won't power up

I have installed a software called Ultra Sigma and that software will let me to print the screen, but I couldn't find the location where has saved the file.
I will look into it more later on today.

[tom66]

Re: Harman Kardon AVR1700 won't power up

You don't need that.

Press STORAGE button.

Then press STORAGE on side menu to select the type used, select Bit Map.

Then press External and New File.

But if you can't figure it out just take photos of the screen.

[tibimakai]

Re: Harman Kardon AVR1700 won't power up

I have just looked up the manual and I have noticed that. In will try it out when I will be home. Thanks

[tibimakai]

Re: Harman Kardon AVR1700 won't power up

Finally I have managed to save them.
First one, is the good channel, second one is the bad channel with the same settings and the third one is still the bad channel, but I made it much more viewable.

[tom66]

Re: Harman Kardon AVR1700 won't power up

The bad channel is essentially silent then.

So, you said it sounded distorted. With a speaker connected to the output, you would say the output is very quiet, almost not there?

[tibimakai]

Re: Harman Kardon AVR1700 won't power up

Yes, I have to be very close to the speakers.
Today, I was measuring with the Ohm meter all the resistors and one of the 22K was showing 0.6 Ohm, but when I have removed the board, it was showing a correct value.
How is that possible?
I went through all the parts on that channel and I didn't find anything bad.
To measure voltages it's very hard, because on top of the amp is the HDMI board.

[tom66]

Re: Harman Kardon AVR1700 won't power up

Where was the 22k? Can you highlight it in circuit?

[tibimakai]

Re: Harman Kardon AVR1700 won't power up

Here it is:

It's late here, see you tomorrow.

[tom66]

Re: Harman Kardon AVR1700 won't power up

Can't see any shorted transistor causing that.

[ben7]

Re: Harman Kardon AVR1700 won't power up

Checked for solder bridges?

What is the resistance across R606?