SOLVED KOT - nothing works at startup

[Bartman101]

Hi y'all, this is my fifth pedal build but this one causes me headaches.

The PCB was slightly different from the one in the manual,
still I think I got everything in the right place
(not certain about the switches though)
Bypassed sounds
When engaged, no leds no sounds.

Traced all connections and resoldered everything
When measuring at the 9v-GND on top
I measure 0V though the 9v power supply is connected

Any help would be appreciated!

 

[temol]

Show us DC jack and it's wiring.

 

[Bartman101]

 

[Bartman101]

There you go!

 

[temol]

Hm.. Did you connect the red wire correctly? Here is the right connection.

 

[Bartman101]

....aaaand.....we have light

 

[Bartman101]

I spend an hour or two thinking those two lugs were connected on the dc connector...apparently they are not



Further test tomorrow, butvthanks already for helping out!

 

[temol]

Well.. they are connected. Until you insert the plug

 

[Bartman101]

Who designed these ?
So far so good, left side of the pedal is working fine, right side has
led lighting up but no sound unfortunally....

 

[temol]

right side has led lighting up but no sound unfortunally....

Now it's time to:
- measure IC voltages,
- look for solder bridges,
- make sure that switch wiring is OK,
- trace the signal with audio probe (this may be your first or second action).

Check the signal in the places marked in red.

 

[Barry]

Doesn't look like here's anything on the Pots to protect from shorting

Edit: I see there are pads on them in the earlier photos.

 

[Erik S]

Looks like you have your in/out jack grounds joined to the DC jack instead of the ground points on the board. I guess that might work if your jacks and footswitches were all grounded to the enclosure, but I don't know if that will work for testing out of the enclosure.

 

[Bartman101]

Probing until there was no sound..one leg of 5he 6.8k still has tone..the other side hasn't. The R still measures 6k8. But after RB10 there's no sound

Resoldering didn't solve the problem. Is this just a bad resistor or a faulty PCB?

Very gratefull for the help, I'm learning A LOT!

 

[Bartman101]

Looks like you have your in/out jack grounds joined to the DC jack instead of the ground points on the board. I guess that might work if your jacks and footswitches were all grounded to the enclosure, but I don't know if that will work for testing out of the enclosure.

Good thinking, I measured and it should be fine but I'll replace those wires asap. Tanx!

 

[temol]

Check for continuity to GND in marked area. You can also check continuity between pin 3 of the VOL-B and RB10.

 

[Bartman101]

All these connections seem legit...but rb11 appears to be shirt circuited to GND...might that be the solution?

 

[Bartman101]

Desoldered rb11, both pads still are connected to gnd

 

[Bartman101]

..removing the wires solved the short circuit....tension mounts

 

[temol]

Maybe there was a single hair of wire causing the short? Replace the wires.

 

[Bartman101]

View attachment 75607
And there we have it....
The 3PDT pcb had a broken connection from FX out to the upper right log.... Very unsexy solution bypassing it but suddenly everything works!!
Thank you all for helping out, big shout out to Temol for pointing a newbie in the right direction! Case closed!