Harman Kardon AVR130 - Issues

[revelations]

Re: Harman Kardon AVR130 - Issues

Ill make a photo of the correct and "wrong"soldering.

And i have not, i was afraid of damaging the working front panel? do you think it won't harm? if i try that

[revelations]

Re: Harman Kardon AVR130 - Issues

You say you soldered them but they may not be correct?, it's only 3 connections, and they are connected together. If they are soldered correctly you should have the fillament light up in the display (can be hard to see) or measure the a/c voltage going to the display. those are the 3 pins on either side of the display tube. and should be about 8.4 volts ac.
Did you try the working front panel on the non working amp? to see if the rest ofthe unit is working.

See attached photo. The working AVR has 8.3/4voltage on those pins, the broken AVR does not. interesting.

But i can't remove all the solder to fix it back to its original situation. is that a problem?

[R_J]

Re: Harman Kardon AVR130 - Issues

That solder is fine, a bit too much solder but will be ok.
The reason you have a display on the working one is because the main transformer is on. If you turn off the amp the display should go OFF and the 8.4 volts a/c will also.
The transformer supplies the a/c voltage to the display filament. so If the amp doe'nt turn on there will be no display.

As for trying the good panel on the bad amp, I ain't saying anything, I would check the voltages on the front panels and compare them, have the working amp turned off so the voltages you are comparing are for a turned off amp.
There is only so much you can do with a meter, I would have had my scope out along time ago.

On page 105 that board CUP11581-5 (the one with the .47 ohm resistors) has a small push button, that is a manual reset, try pushing that and see what happens

[revelations]

Re: Harman Kardon AVR130 - Issues

Ah, ive measurred again and indeed the voltage is going to zero when turned off. Unfortunately I have no scope and they are expensive around here.

I when the system did work the silver one I had already pushed that button and it didnt change a thing. To bad because now I think the system did work, power button went blue and the volume button aswell, just no display. And soon after it didn't turn on at all. So if I resoldered the display it might had worked.

[R_J]

Re: Harman Kardon AVR130 - Issues

It seems odd that someone would unsolder the three display heater pins. Do you know what was done after the amp seemed to work (blue led still came on)?
There is another RESET ic (ic87) I guess check the voltage on its pins 2 and 3 It is located near CN91 Im not sure what it does exactly but maybe its stoping the micro from running.

All that is needed for this thing to function is the standby +5 volts, then it gets a reset and it should work (if the clock osc.) is working and the micro is'nt damaged.

[revelations]

Re: Harman Kardon AVR130 - Issues

It seems odd that someone would unsolder the three display heater pins. Do you know what was done after the amp seemed to work (blue led still came on)?
There is another RESET ic (ic87) I guess check the voltage on its pins 2 and 3

What i did was, after i turned the amp on and saw the blue standby and the volume led on but no display, i turned the device off. openend the case. hit the manual reset. didn't work the first time. so hit it a couple of times (people said that could work)

And then all i did was removing the video input board. to see if something was up, then put it back together. and it stopped turning on, stayed red from that moment.

[R_J]

Re: Harman Kardon AVR130 - Issues

Is the video board back in or is out again? I can't see any problem with having the video board out, the amp should still turn on.
Even if there was a problem on the amp board etc. it should still try to turn on.

[revelations]

Re: Harman Kardon AVR130 - Issues

The video input is connected yes, ive seen videos where people had those prints taken out completely and the machine still turned on, don't believe it matters, since its just an input board

[revelations]

Re: Harman Kardon AVR130 - Issues

So ive measurred everything we have discucced earlier and here's the outcome, it's the same between both units

DEFECTIVE UNIT (SILVER)
BN80 PIN4 = 0v , PIN 5 = 0v
BN88 PIN4 = 3.4v if standby pressed = 0v
BN81 PIN6 = 5v , PIN8 = 3.4v (reset)
L702 = 5v
D761 = 3.4v one side, other side 4.3v
IC72 - > PIN96 - > Q726 = 0v pin1&3
IC72 - > PIN96 - > Q743 = 5v pin1&3
J804 = 0v
IC85 PIN1 =3.4v, PIN2 = 3.4v, PIN3 =0v
J706 = 3.4v
J700 = 0v
IC87 PIN1 =0v, PIN2 =3v, PIN3 =3v

Working UNIT (BLACK)
BN80 PIN4 = 0v , PIN 5 = 0v
BN88 PIN4 = 3.4v if standby pressed = 0v
BN81 PIN6 = 5v , PIN8 = 3.4v (reset)
L702 = 5v
D761 = 3.4v one side, other side 4.3v
IC72 - > PIN96 - > Q726 = 0v pin1&3
IC72 - > PIN96 - > Q743 = 5v pin1&3
J804 = 0v
IC85 PIN1 =3.4v, PIN2 = 3.4v, PIN3 =0v
J706 = 3.4v
J700 = 0v
IC87 PIN1 =0v, PIN2 =3v, PIN3 =3v

[R_J]

Re: Harman Kardon AVR130 - Issues

Well the fault may not be with any of the dc voltages etc. It could be that the microprocessor is either bad or not working due to bad data/internal program
You could try disconnecting the battery for a couple days and see if it works after it sits for a while, There could be a fault with the display ic, ic74 or any of the other ic's on the front panel killing the data or clock lines.
Do any of the ic's seem to be getting hot? or compaired to the working unit are maybe cold and should be warm to the touch

You could try turning the amp on by shorting Q743 (E to C), that will turn on the relay and power up the amp but will not likely give a display

[revelations]

Re: Harman Kardon AVR130 - Issues

Well the fault may not be with any of the dc voltages etc. It could be that the microprocessor is either bad or not working due to bad data/internal program
You could try disconnecting the battery for a couple days and see if it works after it sits for a while, There could be a fault with the display ic, ic74 or any of the other ic's on the front panel killing the data or clock lines.
Do any of the ic's seem to be getting hot? or compaired to the working unit are maybe cold and should be warm to the touch

You could try turning the amp on by shorting Q743 (E to C), that will turn on the relay and power up the amp but will not likely give a display

In standby mode they have the same temp on all ic's, ive also checked the old battery and after a few days it suddenly gave me 3.6v again. So I guess that battery wasn't defect after all. Ill desolder the new battery and it leave it out for a few days

[revelations]

Re: Harman Kardon AVR130 - Issues

shorting those results in no lcd or lights at all. Just the Transformator switching on

[revelations]

Re: Harman Kardon AVR130 - Issues

So I finally had some time to put the battery back, outcome still nothing. So then I thought or actually without thinking I hit the 3 pins on the right side of the lcd, and suddenly the machine turned on. But no lcd display. Tho I had desoldered the pins last time, see photo. Blue standby led turned on, volume turned on, and relays turned on aswell.

[R_J]

Re: Harman Kardon AVR130 - Issues

What do you mean "you hit the 3 pins on the display"? Are you saying that if you desolder the 3 filament pins on the display the unit comes on?
If this IS the case, I suspect there is a broken filament wire in the display and it is shorting to the elements inside the display. I have only seen this happen a couple times before, it is rare but it does happen.
In this picture there are 7 filament wires

[revelations]

Re: Harman Kardon AVR130 - Issues

What do you mean "you hit the 3 pins on the display"? Are you saying that if you desolder the 3 filament pins on the display the unit comes on?
If this IS the case, I suspect there is a broken filament wire in the display and it is shorting to the elements inside the display. I have only seen this happen a couple times before, it is rare but it does happen.
In this picture there are 7 filament wires

Ill try to resolder them. See photo for the 3 pins I touched

[revelations]

Re: Harman Kardon AVR130 - Issues

I resoldered the 3 pins on the right side of the display, now suddenly the display works aswell. But the left side isn't resoldered yet. Photo is left side 3 pins + 1 pin resistor

[R_J]

Re: Harman Kardon AVR130 - Issues

For the FL display to work at all the filament must be on, so I suspect the display leads are actually making contact with the board traces.
Looks like it might be alive.

[revelations]

Re: Harman Kardon AVR130 - Issues

For the FL display to work at all the filament must be on, so I suspect the display leads are actually making contact with the board traces.
Looks like it might be alive.

Yep! Still a bit strange, first time i placed the battery back it didn't work, after hitting the 3 pins it started to work. resoldered those pins and the display works aswell. Great sound, everything works perfectly.

Still it kinda leaves me with an unanwsered question. What was the problem? Especially since i already had resoldered and desoldered the display twice. maybe its a combination of leaving the battery out for so long + display pins back.

I would like to thank everyone for helping, Especially RJ! highly appreciated the help. Thanks!

[R_J]

Re: Harman Kardon AVR130 - Issues

It very well could have been locked up, leaving it unpluged for a while will let the caps discharge, like the ones in the reset circuits and on any of the other ic's. Then when you plug it in again everything gets a fresh start.

One place I have see this happen offten is with remote controls, all of a sudden they no longer work, sometimes taking out the batteries will reset them but many times you need to remove the batteries and also short the battery terminals to drain the internal cap to completely reset the remote.

Well glad to here its all working and I hope it stays that way.

[revelations]

Re: Harman Kardon AVR130 - Issues

Ah interesting. I do have a problem. It's not saving or remembering the frequency for the radio. After a time it's gone. When powered off. The black one does remember it. Any idea where the memory is locaties for that part?