Another BSIAB2 problem

[i2k]

Guys,
Just finished building my BSIAB. I have big problems, tried the search but cannot find any information which related to my problem. So, as a rookie, I really need help here 
I built the BSIAB2 using the layout from and schem GGG, using same values for all components. I've ensured that all the wiring and pin assignment are OK, but the result is sound like real bad, too bad to be described.
After some voltage reading, it seems that the problem related to Q1, Q3 and Q5. Q4 and Q2 are good, the reading are little bit higher than GGG reading, but I don't think that's significant. Following are the reading (using 9v regulated PS, not connected to any guitar or amp):
D1 anode = 8.98
D1 cathode =  8.33v vs 8v on GGG's reading (I think it's only because PS voltage variation, mine seems provide higher voltage)

my reading vs GGG
Q1 (GSD) = 0, 0.644, 4.86  vs 0, 0.95, 4.5 (the G and D seems OK to me, while S is too low)
Q2 (GSD) = 3.97, 4.86, 8.33 vs 3.8, 4.5, 8 (all seems fine for me)
Q3 (GSD) = 0, 29.8 mV, 4.43 vs 0.3, 0.75, 4.3 (D is OK, G is dead, dont know about S)
Q4 (GSD) = 3.98, 4.43, 8.33 vs 3.8, 4.3, 8 (all seems fine)
Q5 (GSD) = 0, 1.23, 3.38 vs 0.5, 0.9, 3.4 (D is OK, G is dead, dont know about S)

Replace Q3 and Q5, same result, conclusion: the problem coming from something else.
I dont  know about Q1 source voltage, do I have to test it with guitar plugged in ?
About Q5 : the G is connected to C12, I've checked that the voltage on C12's leg that connected to the drain of Q3 is OK, but the other end is 0, so that's why nothing is feeding Q5 gate ? Do I have bad caps here ?. The strange thing is: I can detect a small current passing through C12 using my multimeter. But why the voltage is 0 ? I pull out the caps, measured it, the capacitance is OK (22 nf).

I think the same problem applies to Q3, but this time with C4. Everything after it has 0 voltage.

So, what's wrong with my build ? Did I perform a correct debugging steps ? I'm desperate here, please help.

Thanks in advance...

[i2k]

somebody please.... 

[aron]

OK, build an audio probe:
http://www.diystompboxes.com/pedals/debug.html

Now, "listen" to the lug of the switch that has the input signal from the input jack. If you don't hear anything, your input jack is probably wired incorrectly.
If it's ok, listen to the junction of R1 and R2 and if you don't hear something, then there's a problem with your board between the switch and the gate of Q1.
If it's ok, listen to the junction of the drain of Q1 and C4. If you don't hear something, then somehow something's wrong with the first stage (Q1/Q2).
If it's ok, listen to the gate of Q3. If you don't hear anything then the error is between C4 and the gate of Q3.
If it's ok, listen to the junction of the drain of Q4 and C12, If you don't hear something, then somehow something's wrong with this stage (Q3/Q4).
If it's ok, listen to the gate of Q5 and you should hear signal. If not, then then error is after C12 and the gate of Q5.
Try and listen to C13 and if you don't hear something then the error is in the tone section.

Using the audio probe should get you closer to the problem quickly.

Aron

[i2k]

Thanks Aron, I'll try the audio probe tonight. But I would like to know also why I have the voltage reading on one pin of the capacitor, but 0 volt on the other pin. Is this normal ?