Yusynth VCO no audio

[MrSbarre]

Hi,
I just finished building my first Yusynth VCO module, but I have absolutely no sound at the 4 outputs.
I'm using a LM394H (the one with the metal can).
The board is getting 12V (yes, I built the 12v version), I am not an expert so I truly don't know what to do next.

I checked the pin of the LM394H while powering it, and I have 10v between pin 1 and 3, and 8v between pin 4 and 6.
The tempco is well connected, and the thermal coupling is, I think, good enough.

Please help me !

[MrSbarre]

I just replaced the LM394 with two BC547C, and still no sound what so ever...

What do I have to check to isolate the problem ?
Thanks

[MrSbarre]

The LM311p is getting pretty hot when under tension...

[JovianPyx]

Always start out by checking all of the voltages you use. The voltages should be checked at the IC power pins because if there's a bad connection from the rail to the chip and you check the rail then you don't know about the fail at the chip. "no sound" can easily be a power problem.

[MrSbarre]

Thanks for the awnser,
I just checked all the power pins of all the ICs, and they are all getting between 11v and 12v, except the lm394 which is getting 0,5v...

[MrSbarre]

I have 10.5v at the lm394 now...
I truly don't know what to do, I made 3 PCB at the same time, pluged the second one and still no sound is produced..

[wackelpeter]

Maybe post some pics of your pcb and maybe write measurements you already made into the schematics and post it here too…

Do you have an oscilloscope?

[MrSbarre]

Here are some pics of my PCB

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[MrSbarre]

.

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[MrSbarre]

Yes I have an oscilloscope !

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[MrSbarre]

Here are all the mesurement from all the ICs

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[gabbagabi]

do u have a signal there?
if u have a static voltage there, is it changing if u move the freq-pots?

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