First Build - Bit of a mess! Help Required.

[iamtherealmungo]

Hey there,

Some time ago I purchased 5 knob germanium fuzz kit based on a fuzz factory. I purchased the PCB and some of the components from here:

http://www.musikding.de/Kits/Musikding-Kits/Fuzz/The-Factory-germanium-fuzz-kit::2192.html

I sourced the rest of the components and set about making it. I rushed into it hugely and basically jst followed the PCB printing and wiring diagram.. surprise surprise.. nothing. I get no sound, no LED, no sign that anything is working.

Now I'm SURE everyone will say rip it apart and do it again properly.. which is what I intend to do. But this time I wish to actually learn about the circuits and components much much more and learn how to read schematics. Does anyone have some references (online or recommended books) that are good for learning this sort of stuff?

How can I test the circuit as I go? I have a multimeter but I don't know what I'll be looking for around the circuit!

Thanks

[artifus]

http://www.beavisaudio.com/techpages/SchematicToReality/

http://www.diystompboxes.com/smfforum/index.php?topic=29816.0

[Pettol]

Difficult to say of course, but if the led doesn't even light up there seems to be some fundamental error. I'd check the off board wiring. Is d1 correctly orientated? Do you get any sound in bypass mode?
Also you might wanna build an audio probe.

[iamtherealmungo]

Hello,

I wired everything according to the printing on the PCB. I followed the writing diagram but for orientation I had to use the pcb layout.

what is the function of an audio probe? How are they made?

[Kesh]

Audio probes are for later. Like has already been said, first get the LED working and the bypass, then work your way inwards, as it were.

[iamtherealmungo]

When you say audio probes are for later? I don't understand what they're for and why they come later?

Nothing works with the unit as it is.. No LED, No signal/bypass. Is it worth re-wiring the PCB first seperately then assembling the rest of the components?

Thanks

[Kesh]

I mean get the LED and bypass working before worrying about the board.

The only way to debug is to fix one thing at a time. The LED and bypass not working should be a very easy fix, and is to do with the power, switching and other off-board wiring. It maybe that your pcb is fine, but hooked up wrong.

So do not worry about anything as sophisticated as an audio probe until you have fixed basics like LED and bypass.

[iamtherealmungo]

Okay,

I removed the PCB, took a look at the wiring diagram and it all matched up. So I unsoldered everything (off board) and wired it up again. I wanted to check the LED was working so I hooked it up so the battery connector and all I got wsa a flash then it went dead.. So I must have blown the LED>

Why would this happen? Is that normal?

Also, if something is wrong on the PCB.. should the LED and bypass still work?

Thanks

[Pettol]

Kesh is right. Forget about the audio probe.
Do you get 9V where it should be 9V if you measure it (not e.g. -9V)? Are you sure you have connected the DC jack correctly? Remember ground is in the middle (the pin).
Have you perhaps mixed up the lugs of the tele jacks (ring, sleeve, tip)? - There are differences between for example Switchcraft and OEMs.
Short circuit to ground somewhere?
About the LED. If you just hooked it up without a resistor, then, yes, what you saw is normal. You need a resistor as well (use a 2.2K or similar between +9V and LED+).
And yes, even if your PCB is dead you'll get a signal in bypass mode. The LED is partly PCB integrated so I that might not work.

[LucifersTrip]

one of the 1st steps in troubleshooting should be checking & reporting & comparing voltages

see debug thread