Help , No sound from 4 pole mission

All i have to test is a multimeter, can someone guide me to find the problem

Any more information?

Start by checking the power supply. If you don’t have more info to share, it’s hard to pinpoint what to do.

1: Check power supply and trace it along the PCBs.
2: Check the orientation of all ICs
3: Check and reheat all solder joints

all the ics are in good orientation, i did reheat all the solder joints, the digital board is working fine, it receives the midi signals. Maybe i just put a wrong resistor somewhere. And i did a power supply test as shown on the build page.

Do you get signal at one of these points?

Have you soldered the bridge near the output jack?

from those points i read 0v (0.03v), and yes i soldered the bridges.

I want you to check if there is an audio signal at these points, by connecting the point (and ground) to the input of a sound card or amplifier.

No sound from those points . i’ll send a picture tomorrow if it can help.

Do you have sound on the OSC> pin of the control board?

yes i get sound from bridging osc> and vca> . I tried the control board with other filter boards and it was working fine.

I am not sure I understanding the thing about bridging osc> and vca>. Do you have sound on IC1 pin 1?

by bridging i mean connect together. yes sound from ic1 pin 1.

Why did you bridge OSC> and VCA>? - there’s a chance of damaging the ATMega by doing so (you’re shorting two points at a different voltage).

What is the voltage on IC5 pin3; with cutoff = 0 and cutoff = 127?

at 0= 1.842v and at 127= 1.843v

We’ve got a problem here, the filter is always fully closed… I suspect a bad solder joint on the V/Oct trimmer.