G9 Left Channel Troubleshooting

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zaraxisof

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Aug 2, 2017
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Greece
Hello everyone, i have just finished G9. Checked all supply voltages and they are fine. Then connected front panel boards for first audio test. Channel 2 runs ok with some minor issues (the common osc problem, etc, i leave them out of discussion for now).

My main issue is that due to lack of 10pin crimp connectors/molex in my area and the fact that i was in hurry, i went for a custom patent idea for 10 pin board connectors. I used common male-female pinheads and an unused prototype board i had laying around.
As i was in hurry, i cut the big female pinsocket bar with scissors but in instead of 10 females i cut 11 in Channel2.
"No prob, when will connect it i will start from pin2 and above" i thought, BUT when time came, i accidentally connected the male 10 pinheads/protoboard by starting from the first pinsocket of 11 female pin sockets.

So my whole G9 board-panel connections were one connected to its above etc. 1female empty, 1male to 2female, 2male to 3female,...10male to extra 11th(unused) female.
For example, instead of P48 to P48 , i had P48 to Line, Line to From12V, ... Out+ to Out-, Out- to Trafo+ ... and finally "To Output" to "Nothing" (the silly empty pin socket in the end).
In the last pic i show exactly how i accidentally connected them wrong. The extra female 11th pin is marked with orange arrow.

Now for Channel1 i get only hum, no signal output.
Channel2 is ok as i said above.

What should i check first?
 

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zaraxisof

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Aug 2, 2017
Messages
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Location
Greece
Yes indeed. Pic was taken with tubes removed.

Right Channel sounds perfect, I'm amazed, no noise at all ultra clean.
Left Channel only buzz, no output at all, at any inputs. So i assume it has smthng to do with my boards-connecting accident for this channel i described above.

What path could i have damaged by incorrect connecting main-control boards?

Some pics
 

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zaraxisof

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Joined
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Messages
129
Location
Greece
This thread seems to be like my personal diary.

Found out. Unsoldered pad at "To Out 1" trace!

My G9 runs smooth, noiseless and much cleaner than any other pre i own!

Peace 🙂
 

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totoxraymond

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Oct 25, 2013
Messages
144
Location
Paris - France
That missing joint happened to me too often...

You should also check the joint next to it (top left on the image), it looks a little bit weird.

Maybe you already did though...


Enjoy!

Thomas
 

zaraxisof

Well-known member
Joined
Aug 2, 2017
Messages
129
Location
Greece
That missing joint happened to me too often...

You should also check the joint next to it (top left on the image), it looks a little bit weird.

Maybe you already did though...


Enjoy!

Thomas
Yeap i already did it.
Thanks guys.

Is it OK to use 165mA indicator 12V bulb instead of 50mA? I want to go with incandescent E10 as i have already some holders from old era nice looking machines and would live to reuse them.
Can also find 100mA locally but hard to get 50mA here.
 
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