Serendipity: No Bypass, Much Noise

[whitebread47]

So I fired up my etched Serendipity build and....nada ting.  I've looked over it a number of times, no solder bridges, correct component placement/orientation, wiring done as illustrated in build documents, etc.  I'm getting continuity throughout, and see no cold solder joints.  I'm getting 8.95v at the DC jack as well.  The IC (JRC4558D) is the only subbed part and seems to be getting reasonable readings (though I don't know exactly what they should be):

1 = 4.49  8 = 8.95
2 = 4.49  7 = 4.48
3 = 3.05  6 = 4.49
4 = 3.05  5 = 4.44

I'm not sure how to measure the transistors (datasheet for Fairchild 2n7000 doesn't use the "BCE" orientation, which added to my confusion).  Basically, two of the leads on Q1 are reading 4.49, one at 4.16.  Q2 shows two leads at 4.49, one at 4.31.  If there's any more information that would be helpful I can get it.  I'd love to learn a little bit here, so feel free to school me on troubleshooting.  I'll see about getting some pics up here soon, but may be going out of town tomorrow.

Thanks in advance.

[whitebread47]

Here's some added information that I neglected to list in the OP.  I socketed the 2n7000s and omitted the battery snap.  I accidentally soldered the IC socket in backwards, but oriented the IC itself correctly (I couldn't see this causing any issue, being just a socket).  There's no lifted copper on the etch, either.

One more thing, I do not have the LED hooked up right now for testing.  Reason being, I've destroyed some pads on etched boards from desoldering LEDs and was hoping to avoid this.  Could the lack of LED somehow affect the pedal on or in bypass (my gut says no, but I'm a noob).  Also, would a grounding issue affect the bypass signal?  I have not boxed this thing up, so there is nothing to ground the jacks to right now, but I've had previous circuits work without.  Worth asking, I suppose.

EDIT:  Trying to attach photos, but imgur is not working right now for some reason.

[jkokura]

Well for starters, Pin 4 should read 0V, which means you have power on your ground. Find the leak of your power to ground and you'll be a long way on the road.

Jacob

[whitebread47]

Okay, I'm getting 0 now on pin 4.  When I went to retest, I made sure to have a cable in the input jack.  I don't think I had one in there when I got those readings.  Out of curiosity, I threw an LED in there.  The LED activates with the switch normally, but I still get no bypass and a constant loud hum.

I've quadruple checked the wiring and component values/orientations; all good.  I'll snap some photos of the circuit in the morning.  Maybe a fresh go at it will help.

[jkokura]

A hum and no bypass means your jacks are not properly grounded. The fact that you had to plug a cable in to get 0V on pin 4 also indicates you have an issue with your wiring. You should have 0V on that pin all the time.

Jacob

[whitebread47]

A hum and no bypass means your jacks are not properly grounded. The fact that you had to plug a cable in to get 0V on pin 4 also indicates you have an issue with your wiring. You should have 0V on that pin all the time.

Jacob

Hmm, I'll take a fresh look at the jacks and wiring tomorrow.  It's usually best for me to take a break anyways.  That information is good to know, thanks for the help.  I'll see what I can remedy in the morn.

[whitebread47]

I found one wire that wasn't holding too well (can't remember which one).  To test the circuit, I grounded the input and output jacks to an empty enclosure and it worked.

Thanks for the help.  This thing sounds amazing, it was a pleasant surprise!