SOLVED Octagon no wet signal

[NickC]

when i turn the mix knob to wet i have no sound at all
the dry signal and the vol pot is ok

checked voltages at FV-1 pins 6, 8 & 23 - all read 3.3v

 

[Nostradoomus]

Some of your soldering could be cleaned up, this blob in particular looks like it may be trouble. Also get some sort of insulator on the back of your pots just in case.

 

[NickC]

there is plastic insulator on the back of the pots, that blob in the pic look like solder lead but is the transparent things it come out when you solder. i checked the continuity to the pot and it's ok. I also cheked that the blob doesn't short the 2 points.

 

[jwin615]

Did you probe and see if you have wet out of the fv-1?

 

[Feral Feline]

If you probe pin 28 of the FV-1, do you have anything there?
Doh, Jwin615 beat me to it.

If you do have something at pin 28, then keep working downstream from there to the output to see where wet's getting dumped.
Got signal at the TL072's pin 5 and 7? Yes?
I'd suspect the MIX pot, legs 2&3 look like they could use re-flowing the solder.

Check pins 26 & 27, in the photos it looks like a possible short there, but that could be a trick of the light.


If No signal coming out of the FV-1 pin 28...
then do you have signal going into it? Check pin 1 (and 2).


Definitely seems like a job for an audio-probe and work your way through the FV-1...

 

[NickC]

If you probe pin 28 of the FV-1, do you have anything there?
Doh, Jwin615 beat me to it.

If you do have something at pin 28, then keep working downstream from there to the output to see where wet's getting dumped.
Got signal at the TL072's pin 5 and 7? Yes?
I'd suspect the MIX pot, legs 2&3 look like they could use re-flowing the solder.

Check pins 26 & 27, in the photos it looks like a possible short there, but that could be a trick of the light.


If No signal coming out of the FV-1 pin 28...
then do you have signal going into it? Check pin 1 (and 2).


Definitely seems like a job for an audio-probe and work your way through the FV-1...

Thanks i will do these check and let you know

 

[NickC]

i have the mod sound on pin 28 of the fv1 and the ctrl pot 1 2 3 affected the mod sounds, the 8 mode works so the eeprom is ok, i have the dry signal on the tl074 at pin 5 and 7, i have reflowing the pins on the mix knob, nothing change.

 

[NickC]

SOLVED pin 28 of the fv1 needed reflow! the probe was essential forthis! thanks all folks!