Sorry..one more debugging. Hex Sound Fuzz (red llama) from tonepad

[mitzrecords]

http://www.tonepad.com/getFile.asp?id=119

sorry i just posted help for debugging for my rebote delay and i fixed it with all your help! but today i found that my fuzz pedal stopped working.

my Hex Sound Fuzz is little different. It was from some local DIY guitar pedal workshop I attended. different from original tonepad one, it has a selection of low/high(toggle switch). its layout looks like this

http://bp3.blogger.com/_xtvfH1oXNNo/R_a2ij05rfI/AAAAAAAAAV0/Ib5-D3oxYOI/s1600-h/brookelayout.JPG

this was working ok. there was a little connecion loose on output so i wanted to tighten things there so i opened but now there is no sound when the switch is on. when it is off, there is sound but when engaged, no sound.

this was same problem as my rebote delay so i used audio probe to trace it but all i get is deep hum, or normal sound(no fuzz), or no sound anywhere.

i measured the voltage of IC

1 4.21
2 0
3 4.19
4 0
5 4.31
6 0
7 4.3
8 0

9 1.83
10 1.88
11 4.15
12 0
13 0
14 0
15 0
16 0

lots of zeros.

any advice would be highly appreciated!!!

thank you!

[mitzrecords]

i tried audio probe one more time but i get really deep hum with tiny bit of guitar sound or just clean guitar sound.

hmmmm???

[mitzrecords]

any advice welcome

[mitzrecords]

anyone??

[Mark Hammer]

Exactly what voltage is it supposed to be operating on?  9v?  5v?  It's hard to know what to make of the voltages listed if we know nothing about the circuit itself.

You'll need to provide more context if you want an useful answer or want to provoke interest.

[mitzrecords]

Exactly what voltage is it supposed to be operating on?  9v?  5v?  It's hard to know what to make of the voltages listed if we know nothing about the circuit itself.

You'll need to provide more context if you want an useful answer or want to provoke interest.

sorry mark. im pretty new to this..

it operates on 9v.

[mitzrecords]

really weird thing is my girlfriend was using it but there was no sound but it was only loose jack or something so she pushed in on output jack harder and started working.

so after practice, i opened up to tighten things. but now it stoped working..

so it might be a lifted wire or   i did most of things like resolder and replaced jacks.

i think im gonna try to replace switch tomorrow.

thank you always!!! for any input.

[Mark Hammer]

sorry mark. im pretty new to this..

it operates on 9v.

No problem.  There is always a learning curve, right?  There is even one for me, too.  When the header read "hex sound fuzz", I thought yo were referring to some circuit for a divided pickup - a "hex" fuzz - and I was a little confused.  That's why I foolishly asked about the supply voltage.  Looking at both the Tonepad layout for the Anderton/Huge circuit, and the layout you linked to, I now realize you were talking about the Tonepad layout for the Anderton Tube Sound Fuzz that uses a hex invertor.  My bad.

With a 9v battery, you should have 9v at pins 1, 3, 5, 7, and 11, as per the layout.  Since pin 10 is the final chip output pin before going to the volume pot, there ought not to be anything particularly measurable there when no signal is applied.  I'm not nearly as much a whiz with voltage readings as some of the other folks here, but my immediate sense is that, with all those readings in the 4-4.5v range that ought to be 9v, and with that 1.83v reading that ought to be much lower, AND with the 100R/1k resistor sitting so perilously close to the .05uf cap that SHOULD be blocking DC at the finally invertor's input, maybe you ought to check whether there is any short between that resistor and that cap.

It may not be necessary in your case, but I often recommend to novice builders that they take a cotton swab and apply some alcohol or some methyl hydrate to dissolve the flux buildup around the solder joints on the board, just so they can get a clearer view of the PCB.  Sometimes you can think its only flux but it is actually a solder bridge, and sometimes you can think it is a solder bridge but its only flux.  Helps to be able to visiually distinguish the two easily when debugging.

Keep us posted, and thanks for your patience and persistence.

[mitzrecords]

thank you so much, mark.

i tried to look for shortings but there seem to be no shortings there.

hmm im really stuck now.

[dxm1]

Ah, the familiar "It was working, then I boxed it up, and now no sound" scenario...

This has probably happend to just about everyone at one time or another.  Usually,
this type of problem involves one of three things:

1)  Bad off board wiring connection.  One or more of the wires from the board to the
    pots, jacks, or switches is not securely soldered or broken (under the insulation, if
    using stranded wire).  Easy to check.  Just wiggle each end of each wire with the
    effect engaged and sound applied to the input.  This also includes loose jack connections
   (if you're counting on the jacks to transfer ground through the enclosure.)

2)  Some part of the circuit shorted to the enclosure (if using a metal box).  This could
    the circuit board itself, or an off board wire connection.  Again, the wiggle test...

3)  Power short - if power was applied when disassembling the effect, 9v and ground
    could have been momentarily shorted.  Use the info in the Debugging thread, Wiki,
    and at GEO about debugging power shorts.

[mitzrecords]

hi, thanx for advice.

i checked everything and i found a one shorting spot.

after that voltage measured 5.21v on where it was 4v
for other pins which measured 1.8 or so, went up to about 2.3..

but same result for sound, bypass is fine but no sound of fuzz.

[mitzrecords]

it works now!!

i think i fixed it but i had output and input other way around. haha i feel really stupid now.

but it works!!

thanx!!!!!!!