Brown Bettery - No Power

[DeuceOfAllTrades]

I finished putting together the Brown Betty, and it won't power up (no LEDs, no output). I traced the entire power section using the schematics, which tested good for voltage. I get no voltage on the audio side when clipping the multimeter to ground. I've double-checked my wiring and confirmed continuity for all wires. This is my 6th or 7th project, and the first time I've run into problems. I'm not sure what to do next. Any suggestions? Even a link to another forum or walkthrough on this type of issue would be great.

-- Note, I removed the status LED when disassembling from the enclosure. I had a jumper in just to confirm voltages. I'm still confused as to how there is voltage across the status LED but it doesn't light up. I know my leads aren't trimmed well enough - I need new cutters as I can't get tight enough to the board. I've double-checked that none are bridged or contacting the pots.

 

[Chuck D. Bones]

Things you can do:
1) Take a pic of the component side of the board straight on so it's easier for us to read the parts.
2) C2 & C6 are pretty fat for 47pF capacitors. Verify that they are 47pF and not something much larger.
3) Verify C8 & C15.
If that still doesn't fix it, move on to step 4.
4) Measure and report the DC voltages on all of the IC pins, power on, no signal. Pin 4 is ground, so you don't need to measure those. Pin 8 should be +9V, everything else should be close to +4.3V.

What is the voltage across the LED? Should be around 1.6V for a red LED. If the voltage is significantly more than that, then either the LED is blown or it's hooked up backwards.

 

[moonlightpedalbuilds]

Check your breakout board for the 3pdt switch. I don’t think that would work for PedalPCB pcbs. That needs 9v power. In, 9v, Gnd and Out. PedalPCB is In, Gnd, SW and out. Are those tayda breakout boards? I would recommend PedalPCB breakout board.

 

[DeuceOfAllTrades]

Check your breakout board for the 3pdt switch. I don’t think that would work for PedalPCB pcbs. That needs 9v power. In, 9v, Gnd and Out. PedalPCB is In, Gnd, SW and out. Are those tayda breakout boards? I would recommend PedalPCB breakout board.

They are generic breakout boards (I got 10 boards and 3PDT switches for $15). I confirmed the traces are identical, but I'll wire a 3PDT direct just to make sure. 9v is only required if adding a CLR and LED to the switch. The 4 I have wired are In, Out, Ground, and L (LED).

By the way, I like all the candy you have in there. The molex adapters and plastic pot covers are a nice touch.

 

[moonlightpedalbuilds]

Post a pic of the breakout board. I’m curious if the four output holes matches the PedalPCB input holes.

 

[moonlightpedalbuilds]

Also check underneath the second row pot if they are touching the leads on the pcb.

 

[moonlightpedalbuilds]

check your C2, C6 as mentioned by Chuck.

and these....
C7 47N
C8 470P
C9 220P

 

[DeuceOfAllTrades]

I made a few oversights when ordering caps. C2, C6, C8, and C15 are 1000 VDC 2.5% tolerance, but are indeed the correct capacitance. The ceramic caps (C7 and C9) are what I had laying around. They are also correct values. Verified no shorts between pots and PCB (I might throw some electrical tape on the pots just to make sure). I probably won't get to voltages until tomorrow, though I think they tested good for the IC's.

 

[Chuck D. Bones]

They do not match.
The board in the pic is: GND OUT LED IN (imagine it flipped over with the I/O pads at the top)
PedalPCB boards are: IN GND LED OUT

 

[Nostradoomus]

It’s wired correctly in the first pic...soldering on the I/SW/GND/OUT on the PCB looks a bit of a mess tho, could be a short there

 

[DeuceOfAllTrades]

Most of that is a poor reflection, but I will check to make sure they aren't shorted. Thanks for the help - I'll get to work recording voltages and see where I end up.

 

[Barry]

They do not match.
The board in the pic is: GND OUT LED IN (imagine it flipped over with the I/O pads at the top)
PedalPCB boards are: IN GND LED OUT

It looks like his wires crisscross though, as long as they go to the corresponding letter shouldn't matter

 

[moonlightpedalbuilds]

To test, try to bypass the 3pdt. Input wire(blue?) directly to the input of the PedalPCB board. Output wire too.

 

[Nostradoomus]

I would definitely suggest making a test box if you are fairly new to the game...it helps to narrow down problems like this.

 

[zgrav]

using a board for the footswitch that has LED mounting holes can also be confusing when connecting to a PCB that also has LED mounting holes.

 

[DeuceOfAllTrades]

Yeah, a test box is definitely on the list of things to do.

I ruled out 3PDT problems. I was able to get two of the four LEDs to light up, and there is now audio through the pedal, although it's just a high pitched squeal. I'm getting closer. I still need to test voltages.

 

[moonlightpedalbuilds]

Yeah, a test box is definitely on the list of things to do.

I ruled out 3PDT problems. I was able to get two of the four LEDs to light up, and there is now audio through the pedal, although it's just a high pitched squeal. I'm getting closer. I still need to test voltages.

One side would light brighter than the other.