BMP help please

[sam-sg]

Hey I'm just 'finished' building my bmp replica of off GGG.com and afterplugging in to test when turned on the LED lights up but there is no sound whatso ever. bummer when turned off everything is fine all bypassed and lovely.

I looked on the ggg website today seeking a new parts layout to check over everything but they have gone and changed it so if anyone has one they could send me id be eternally grateful.

also i was just wondering if i could have broken any of the components while soldering. is there any way of telling? (none have gone black but that does that necessarily tell you its broke?)

all the parts are the right values etc i just want to know if Ive wasted my hard earned money

thank you

[beens]

This is usually what happens every time i build something, and every time I dig out my homemade audio probe and find it is just a stupid mistake like a short or the wrong orientation of a transistor. http://www.diystompboxes.com/wiki/index.php?title=Debugging Here you will find info on debugging, how to build a probe and how to use it.

[sam-sg]

thank you though ill need to buy  the things for that i most likely will for future projects are you sure i wont have blown any diodes as my dad said that but i dont know if hes just guessing on his very limited knowledge. should i put electrical tape around all the conacts on pots and the switch to make sure nothing is touching?

thank you so much by the way

[beens]

If you have used lots of heat for a long time your diodes or transistors can have been ruined. I've never killed any of them myself and I have not been very careful so I dont think that is likely. But the audioprbe thing is very useful, you just need an old guitarcable and a .1microfarad or larger C. By using this you can tell where in the circuit the audio disappears, and where to concentrate your debugging.

It is always a good thing to check all your soldering points too, use a magnifying glas and see if there are any small bridges of solder anywhere. Also check the pinouts off the transistors, and the polarized caps too.

[sam-sg]

right when i can i will buy a .1uF cap. , use an old patch cable and test everything but in the meantime ill look for brodjes of solder and remove any of them. youve been a real big help thanks a lot  i owe you 

[beens]

No problem! Hope you'll sort it out. Let me/us know how it works out.

[sam-sg]

so with the audio probe all i do is touch each solder point and if it makes a noise good if it dont bad. and if it doesnt re solder it and  should be         a-ok. am i right?

[killerkev]

The audio probe is a great way to test the circuit  . Besides the capacitor and cable, you'll need a mono jack to snap the cable in. Hook up the negative to a ground on the input jack or the board. Then take the positve and start poking around. You will need someone to constantly strum the guitar as you probe or if you have a recorder you can just hit play and start probing like I do. Some like to start from the output and work their way back to the input but I like to start from the first input to the board...but first connect the positive to the positive of the input jack to ensure that you can hear signal at it's first entry point then start at the signal's first entrance to the board. Follow the path as stated on the schematic or layout.  If you have a multi meter you could always test the voltages at each transistor pin, record the voltages at each pin (Q1, EBC. Q2, EBC. etc) and post what you got..... . I built my first project on the same pedal from GGG and it worked the first time I plugged it in. Are you sure the transistors are oriented the right way? I've done that in the past..........Also check your traces... are there any broken traces that you didn't realize?  What technique did you use to etch the board or did you just buy one from GGG? This should be easy to fix the problem... search and don't get discouraged....when discouraged the obvious is missed and then turn to the wonderful DIY community!