Gravitation Reverb DOA Troubleshooting

[swelchy]

Well... Boxed it up and confident all is well and I only get a bypass signal and no led. I've double checked.. no solder bridges best I can tell.. I took it back out of enclosure and hooked it up... changed the footswitch to see if that was the deal.... still notta. I;ve recorded the voltages on the IC's in the photo

 

[zgrav]

you need to post clear pictures of both sides of your board so we can help you identify issues to check. the schematic is ony useful when it can be compared to what you have going on with the PCB. as noted in many troubleshooting posts: examine the board for shorts between parts and where wires connect to the board and to the footswitch; carefully confirm part values on the resistors and capacitors by reading the bands on the R and values on the C; make sure the ICs are oriented correctly. since your LED is not lighting up you can measure voltage there and see if you either have no power on the + side, no ground on the -, or maybe it is oriented incorrectly.

 

[swelchy]

 

[swelchy]

 

[phi1]

your IC voltages look correct. Most likely IC1 pin 3 is actually sitting at ~3.9v like the rest of the pins, but that 1M resistor to Vref, and a (probably) low input impedance on your meter combine to show the lower voltage. This happens often to me with a cheap meter if the pin3 to vref is 1M. Only one thought, 7.9v on pin 8s does seem a tad low. Makes me wonder if there's something going on with power (like a problem with the 5v regulator pulling extra current or something).

Nothing jumps out after a quick look at your board, except all the components not yet installed at the time of the picture.

I recommned:
1. check for 5V on BTDR pin1
2. construct a small audio probe and begin going through the signal path on the schem to see where signal is lost.

 

[swelchy]

you need to post clear pictures of both sides of your board so we can help you identify issues to check. the schematic is ony useful when it can be compared to what you have going on with the PCB. as noted in many troubleshooting posts: examine the board for shorts between parts and where wires connect to the board and to the footswitch; carefully confirm part values on the resistors and capacitors by reading the bands on the R and values on the C; make sure the ICs are oriented correctly. since your LED is not lighting up you can measure voltage there and see if you either have no power on the + side, no ground on the -, or maybe it is oriented incorrectly.

Posted pictures during the build.. as you can see the brick and pots obscure the back of pcb.. I meticulously measured every component for tolerance and soldered o e at a time… trimmed one at a time.. went over the fro t and back of board and looked through magnifier to inspect for bridges…This is probably my 20th pedal pcb build and 99% of the time I complete build and put in enclosure to just go for it… this is the 3rd pedal I’ve had not work right outta the gate. I do need some more provisions at my bench like a little practice amp and a bench power supply… and I have yet to dive into audio probing.

 

[zgrav]

Posted pictures during the build.. as you can see the brick and pots obscure the back of pcb.. I meticulously measured every component for tolerance and soldered o e at a time… trimmed one at a time.. went over the fro t and back of board and looked through magnifier to inspect for bridges…This is probably my 20th pedal pcb build and 99% of the time I complete build and put in enclosure to just go for it… this is the 3rd pedal I’ve had not work right outta the gate. I do need some more provisions at my bench like a little practice amp and a bench power supply… and I have yet to dive into audio probing.

the audio probe is easy and inexpensive to build and can save you hours of time troubleshooting a problem in your build. easier if you have a sound to play into the pedal while testing (a looper is good, much easier than having a guitar in your lap while tracing the audio signal)

 

[zgrav]

those pics are from your assembly, right? which explains why the pots were not yet on the board. nice detail on the photos and a clean looking build. start checking to figure out why the LED is not coming on when the pedal is engaged. and spend a few minutes putting an audio probe together. if you have the pedal out of the box, post some pics showing the wiring to the board, switch and jacks.

also -- have you confirmed that your footswitch contacts are still working when it is switched. could be a bad switch.

 

[swelchy]

light comes on out of the enclosure... put it all back in and no go... all the pots have plastic sleeves on them... i clEARANCED THE BOX TO MAKE SURE JACK IS NOT HITTING ANYTHING... GETTING VOLTAGE WITH mm ALL OVER THE PLACE... EVEN SHOWS 9V TO ONE LEG OF THE MM... CHANGED SWITCH.. CHANGED 9V JACK... IM ABOUT TO THROW IT IN THE TRASH..LOL

 

[zgrav]

would be good to find out how far the audio is getting through the circuit before it stops, since finding where it stops is the best place to look to fix the problem. the audio probe is not much more than a couple of clips, a capacitor and a piece of wire.

if you are fed up with working on it for now, set it aside and pick it up again after a few successful builds.

 

[music6000]

light comes on out of the enclosure... put it all back in and no go... all the pots have plastic sleeves on them... i clEARANCED THE BOX TO MAKE SURE JACK IS NOT HITTING ANYTHING... GETTING VOLTAGE WITH mm ALL OVER THE PLACE... EVEN SHOWS 9V TO ONE LEG OF THE MM... CHANGED SWITCH.. CHANGED 9V JACK... IM ABOUT TO THROW IT IN THE TRASH..LOL

You need to post Pictures of Both sides of current Build with Footswitch connections, Input & Output jacks & Power jack connections.