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Projects => Tech Help - Projects Page => Topic started by: dcribbs1412 on July 07, 2010, 02:24:18 AM

Title: Firebomb problem
Post by: dcribbs1412 on July 07, 2010, 02:24:18 AM
few shots of Firebomb build
both led lights work...no sound...no bypass sound :-[
ticking sound with master dimed...leds also get dimmer as master is turned up ???
pot? switch?
any comments are appreciated
http://i1018.photobucket.com/albums/af301/dcribbs1412/pedals/Firebomb/glitterrattii003.jpg (http://i1018.photobucket.com/albums/af301/dcribbs1412/pedals/Firebomb/glitterrattii003.jpg)
http://i1018.photobucket.com/albums/af301/dcribbs1412/pedals/Firebomb/firebomb005.jpg (http://i1018.photobucket.com/albums/af301/dcribbs1412/pedals/Firebomb/firebomb005.jpg)
http://i1018.photobucket.com/albums/af301/dcribbs1412/pedals/Firebomb/firebomb006.jpg (http://i1018.photobucket.com/albums/af301/dcribbs1412/pedals/Firebomb/firebomb006.jpg)
Title: Re: Firebomb problem
Post by: stecykmi on July 07, 2010, 05:26:29 AM
First thing's first, figure out the switching problem. Double check against your wiring diagram. A perfect circuit is useless if it's not switched correctly. So get at least the bypass working before you move on.

If you have a DMM (if you don't, you should!), check continuity for ground on jacks, switches, pots and on the board (compare to the circuit diagram). Keep an eye out for stuff that's shorted to ground or stuff that's floating when it shouldn't be.

Check the voltage at the drain of each of the mosfets (should be something like 8V, not sure offhand). Then check the voltage at the gate (should be really small, in the mV range). Keep in mind this is my really quick analysis without any numbers so if stuffs really off, don't freak out because I'm not certain.

If you're still stuck, can you post a picture of the solder side of the board? It's probably easier to troubleshoot from that side.
Title: Re: Firebomb problem
Post by: madbean on July 07, 2010, 12:40:26 PM
You've got a solder bridge between the Master vol and one of the led's or the 9v rail, I think. Or, the grounding isn't correct. Those are the only two things I can think of that would make that control affect the LED.

stecykmi is right on. I would disconnect it from the switching altogether and verify that the circuit works correctly first.
Title: Re: Firebomb problem
Post by: dcribbs1412 on July 07, 2010, 08:24:45 PM
thanks guys
i'm on it ASAP
Title: Re: Firebomb problem
Post by: PeterMorton on July 07, 2010, 09:05:17 PM
Quote from: madbean on July 07, 2010, 12:40:26 PM
You've got a solder bridge between the Master vol and one of the led's or the 9v rail, I think. Or, the grounding isn't correct. Those are the only two things I can think of that would make that control affect the LED.

stecykmi is right on. I would disconnect it from the switching altogether and verify that the circuit works correctly first.

How do you go about this? With an audio probe?
Title: Re: Firebomb problem
Post by: dcribbs1412 on July 08, 2010, 01:43:51 AM
Thanks guys I got it
stecykmi wrote:
QuoteFirst thing's first, figure out the switching problem. Double check against your wiring diagram. A perfect circuit is useless if it's not switched correctly. So get at least the bypass working before you move on.
first problem...wired wrong.... noob mistake :-[
madbean wrote:
QuoteYou've got a solder bridge between the Master vol and one of the led's or the 9v rail, I think. Or, the grounding isn't correct.
yep second problem...grounding not right :-[
thanks for the quick accurate diagnosis gentlemen
your knowledge is greatly appreciated

will post pics as soon ASAP
thanks again
Title: Build done
Post by: dcribbs1412 on July 08, 2010, 03:30:23 AM
Pics of the finished pedal (good enuff 4 rocknroll)
really like the clean boosts this pedal gives
thanks madbean 8)
http://i1018.photobucket.com/albums/af301/dcribbs1412/pedals/Firebomb/firebomb008.jpg (http://i1018.photobucket.com/albums/af301/dcribbs1412/pedals/Firebomb/firebomb008.jpg)
http://i1018.photobucket.com/albums/af301/dcribbs1412/pedals/Firebomb/firebomb009.jpg (http://i1018.photobucket.com/albums/af301/dcribbs1412/pedals/Firebomb/firebomb009.jpg)

again any and all comments are appreciated
thanks
Title: Re: Firebomb problem
Post by: madbean on July 08, 2010, 09:12:52 AM
Righteous. I love it. What font is that, may I ask?
Title: Re: Firebomb problem
Post by: dcribbs1412 on July 09, 2010, 02:12:14 AM
madbean wrote:
QuoteRighteous. I love it. What font is that, may I ask?

thanks
i'm really diggin this pedal ;D
font is JazzText