Noob Debugging Help

[shiner_man]

Hey ya'll.

I just finished up a Catalinbread Dirty Little Secret clone using the following vero layout:



The true bypass works fine but when I engage the pedal the sound goes completely dead.  It's like I've built a kill switch.

Anyway, I was probing the circuit and I'm getting normal voltage readings until I get to C5 (50nf cap).  I get a voltage reading
on one side but the other side gets no voltage reading whatsoever. 

Is this a sign that the 50n cap is the problem?  If so any suggestions on what to do?  I desoldered it and soldered it back on
but I'm still getting the same readings.

Any help would be greatly appreciated.

Thanks in advance.

[shiner_man]

Here are the transistors readings I got:

Q1
C=9.15
B=5.56
E=4.36

Q2
C=5.56
B=1.36
E=0

Q3
C=9.15
B=5.12
E=5.56

Q4
C=9.15
B=4.43
E=4.43

Q5
C=0
B=0
E=0

Q6
C=9.15
B=8.68
E=9.15

[shiner_man]

I posted the wrong values above.  Here are the correct ones.

Q1
Drain=9.15
Source=5.56
Gate=4.36

Q2
Drain=5.56
Source=1.36
Gate=0

Q3
Drain=9.15
Source=5.12
Gate=5.56

Q4
Drain=9.15
Source=4.43
Gate=4.43

Q5
Drain=0
Source=0
Gate=0

Q6
Drain=9.15
Source=8.68
Gate=9.15

Is this indicative of a problem with Q2?  I'm not an expert by any means but that Gate reading 0 doesn't seem right to me.

[jkokura]

Q5 show's there's definitely a problem in there somewhere.

Have you tried audio probing yet?

Jacob

[shiner_man]

Q5 show's there's definitely a problem in there somewhere.

Have you tried audio probing yet?

Jacob

No, I haven't.  I guess that's the next step.

I'm really confused though.  C14 has a voltage reading of 9.23 volts on one side and a reading of 0 volts on the other.

Why am I getting no power in certain parts of my circuit?

[Govmnt_Lacky]

Q5 show's there's definitely a problem in there somewhere.

Have you tried audio probing yet?

Jacob

+1

Also a link to a schematic would not hurt! 

[shiner_man]

Here's the schematic:

[Govmnt_Lacky]

I could be wrong but.... something tells me that the numbering on your vero layout DOES NOT match the numbering on the schematic you linked.

According to the VERO... Q2, Q3, Q4, and Q6 should all have V+ on the Drain.

According to your SCHEMATIC.... Q2, Q3, Q6, and Q5 have V+ on the Drains.

ALSO: Check the orientation and placement of C23 (Which should be C13 according to your schematic). I do not think it is correct on your vero layout. Plus, I think Q4, Q5, and Q6 are LABELED wrong.

[shiner_man]

I could be wrong but.... something tells me that the numbering on your vero layout DOES NOT match the numbering on the schematic you linked.

According to the VERO... Q2, Q3, Q4, and Q6 should all have V+ on the Drain.

According to your SCHEMATIC.... Q2, Q3, Q6, and Q5 have V+ on the Drains.

Apparently the vero layout has been done by over 20 people and it's worked for them.  I was told the vero was based off of this schematic but
I could be wrong.

Curiously, I'm unable to get an ohm reading from R6 and R13 from the vero layout.  It appears that these resistors are not reaching ground.

Does that make any sense?

[shiner_man]

I just noticed something.  I actually used the following vero layout for mine:



C4 is reversed in this one as opposed to the other one. 

Could this be causing the problem?

[shiner_man]

FYI, reversing C4 as shown in Rev 3 fixed it.  It sounds great!