Help! U Boat not working

[bifbangpow]

Project I'm using: http://diy.thcustom.com/shop/u-boat-v1-1-pcb/#

So I get a clean sound, and the LED lights up properly, but when the effect is "Activated" by the footawitch, I get no sound.

My pin readings:

IC1:  (1) 0 (2) 0 (3) 0 (4) 0 (5) 0 (6) 0 (7) 0 ( 1.12 (9) 1.5 (10) 3.5 (11) 0 (12) 2.7 (13) 1.3 (14) 1.1

IC2:  (1) .15 (2) 1.7 (3) 0 (4) 0 (5) 0 (6) 0 (7) .03  ( .02

IC3: (1) 0 (2) 0 (3) 0  (4) 0 (5) 0 (6) 0 (7) 8.0 ( 0 (9) 0 (10) 0 (11) 0 (12) 0 (13) 0 (14) 0

IC4: (1) 4. (2) 1 (3) 1 (4) 1.4 (5) 0 (6) 0 (7) 0  (  .02

And the one transistor is around 8.

Here's a picture.  I've rewired the whole thing once, and resoldered nearly every joint.  I dunno what the problem is.

[thermionix]

footawitch

sorry.

[jez79]

.

[PRR]

Leave the jokes for later.

> My pin readings:

IC1 IC2 and IC4 do not have 9V (or 8V) anywhere; they have to to work. I can not tell if this is measurement error or a build error.

You expect IC1 IC2 IC4 to show Zero on one pin, +9V on another pin, and +4.5V on the rest of the pins. Start by finding what happened to the Zero and +9V.

[highwater]

How do you have 16 pins worth of voltage readings on IC1 when it's a 14-pin IC?

Edit: Same question for IC3.

[antonis]

Re-check your 3PDT switch wiring...!!!

[bifbangpow]

Leave the jokes for later.

> My pin readings:

IC1 IC2 and IC4 do not have 9V (or 8V) anywhere; they have to to work. I can not tell if this is measurement error or a build error.

You expect IC1 IC2 IC4 to show Zero on one pin, +9V on another pin, and +4.5V on the rest of the pins. Start by finding what happened to the Zero and +9V.

So yeah the IC1  has 1s and zeros on all the pins.  The IC4 has no power at all.  What could cause this?

[bifbangpow]

Re-check your 3PDT switch wiring...!!!

Ive checked it a few  times.  Are you seeing something I'm not?

[anotherjim]

Something fundamentally wrong with power supply. Wires appear to be in the right places at DC socket etc. Can't really see the 3PDT wiring all that well.

If you took those measurements with battery power -  was there a plug in the input jack to switch the ring connection on?

As you have sockets for all those IC's, try to test voltages on the sockets BEFORE you fit the chips. Reverse power can permanently damage them, even from the battery.

Many builders like to try to go to a sound test right after the last solder joint is made. If it works first time, you may be pleased with yourself, but there are never any actual prizes awarded for this achievement, not even a cold half-eaten sausage
Instead, what usually happens, is that it don't work and you have the entire assembly to look for bugs. Some of those bugs may be dead chips fried in haste!

[Kipper4]

I fried a TL074 in my latest SVF. I should have checked the pinout before doing the layout.
More on this later.

No prizes you say not even a cold half-eaten sausage.



I go be hungry....

[anotherjim]

Let's hope Bifbangpow didn't fry anything - there is a protection diode on the board - I think it's more likely there's a power connection not getting through.

This is only my criterion for prize giving. It carries no authority. Any hunger pangs are purely virtual.

Work first time without any stage testing = No prize ('cause that was just lucky).

No stage testing, didn't work but fault/s were found & fixed = 1 sausage, no sauce or trimmings.

Work first time after stage testing (with or without any faults found & fixed) = Plate of hot sausages, fried  battered onion rings plus any sauces, relish etc.

Vegetarian? Don't panic. All ingredients are vegetarians.

[pinkjimiphoton]

remember, FLUX is CONDUCTIVE.

i would run a sharp knife between all the traces where applicable, and get all the flux off the soldered side of the board.

pull the dead chip out and check the voltages on the socket itself.

if you get normal voltages, the chip is toast. if you get none, you have a problem with your power supply, likely a solder bridge somewhere.

i often use my meter lead to scrape between solder points. don't go crazy, but make sure each node is clear of bridges and flux (flux scrapes off pretty easily, i use pot cleaner and blast the board off with it to clean it... non lubed stuff only tho)

then put your continuity/diode/beeper check on in your meter, and go from node to node to make sure stuff is connected as required.

if ya get the circuit up and running, yeah!!

if ya don't, make an audio probe and work your way thru the circuit from the input to the output. check each joint. when the sound disappears, that's your problem.

i've had this happen many times where resistors will fail internally on one end or the other... they look fine, but break continuity and when ya move them, they fall apart.

good luck!!

[thermionix]

remember, FLUX is CONDUCTIVE.

Are you sure about that?  I've never seen it cause a problem in 450v circuits, much less 9-18v.  It could have conductive bits trapped in it, however, I suppose.

[pinkjimiphoton]

i'm wrong in fact.   

its not the flux that is conductive, but the corrosion it causes over time...
my stuff gets rode hard and put away wet in a temp range of minus 10 or so to about 110 degrees. so i'm sure it gets condensation, not to mention spilled tequilla and other such tragic abuses

found this on google.

Is flux electrically conductive?
Flux from 'No Clean' solder processes can cause reliability problems in the field due to aggressive residues, which may be electrical conducting or corrosive in humid environments. The solder temperature during a wave solder process is of great importance to the amount of residues left on a PCBA.
Effect of solder flux residues on corrosion of electroni
ieeexplore.ieee.org/xpls/abs_all.jsp?arnumber=4914727

i guess the key word is MAY


i had always been told to clean that s#17 up in electronics class by mr. k, who was a whole trip of his own....

f*ckin' peckerheads was what he called us all, man, them old school guys had some colorful language

[bifbangpow]

remember, FLUX is CONDUCTIVE.

i would run a sharp knife between all the traces where applicable, and get all the flux off the soldered side of the board.

pull the dead chip out and check the voltages on the socket itself.

if you get normal voltages, the chip is toast. if you get none, you have a problem with your power supply, likely a solder bridge somewhere.

i often use my meter lead to scrape between solder points. don't go crazy, but make sure each node is clear of bridges and flux (flux scrapes off pretty easily, i use pot cleaner and blast the board off with it to clean it... non lubed stuff only tho)

then put your continuity/diode/beeper check on in your meter, and go from node to node to make sure stuff is connected as required.

if ya get the circuit up and running, yeah!!

if ya don't, make an audio probe and work your way thru the circuit from the input to the output. check each joint. when the sound disappears, that's your problem.

i've had this happen many times where resistors will fail internally on one end or the other... they look fine, but break continuity and when ya move them, they fall apart.

good luck!!

Should the voltages on the socket be the same as they should have been for the chip? 
And I've always had trouble building an audio probe because I'm never sure if Imd oing it right.

[highwater]

I see in the build-instructions PDF that C14 (blocks DC from reaching the output) should be installed backwards from what is silkscreened on the PCB. Yours looks to be installed according to the silkscreen. It's bad for the cap, and will eventually cause problems of it's own...

I can't imagine how that would cause the problems you're having, but it's worth fixing anyway.

---

Should the voltages on the socket be the same as they should have been for the chip? 

If it's the pin for power or ground, it should be nearly the same with-or-without the chips in the socket (there are exceptions, but this circuit is not one of them).

Aside from that, maybe... but probably not. This circuit has a few IC pins that will (should) have about 4.5v whether the chips are installed in the sockets or not, but most of the pins that should have 4.5v with the chips installed will have 0v without it.

---

P.S. - for reference purposes, there is a previous thread from the OP on this same build, regarding a problem that was resolved by replacing the stompswitch.

[Groovenut]

R17 looks like it's missing in the pic. That will cause issues for sure. Perhaps it's on the other side and I cant see it?

[jez79]

I originally posted about r17 but after reading the build docs' realized it is optional (depends on which Ic is used)

[anotherjim]

Should the voltages on the socket be the same as they should have been for the chip? 

It isn't the intention to see the exact voltages that will be there with the chip present, but to check that there is no dangerous fault (dangerous for the chip). At the very least this might catch out if you fitted the socket the wrong way around, which is one of easiest mistakes no matter how experienced you are.

The scheme doesn't show pin numbers, but if that's the case, I would urge downloading the chip datasheet, if only to see the correct pin numbering.

First, the op-amps. Apply power and check for correct polarity supply voltage where the wires connect on the board.

If you first put the neg probe on the socket -V supply pin you should pick up the supply voltage on the +V pin AND do make sure it's a + reading like "8.86V" and NOT negative like "-8.86V" OR the wrong range like "8.86mV". If you don't have this right, either...
It's not actually powered due to mistake/wiring error.
You have the wrong pins.
The power to the board is reversed.
The power to the board is being shorted out.
The socket pin is not soldered.
A pcb track is broken.
... a lot of things checked for with this one simple test.
If power pins are ok. Keep the neg probe in place and see what volts is on the other pins. Op-amp circuits will usually have the reference voltage (+4.5) or less on all the input and output pins.

You also have a logic chip, the 4013.
Same check for power pins.
Look at the scheme. Only its power pin should have +9v, all other pins probably 0v either because connected to ground or nothing at all. There is a Q output to the JFET diode which might well show something between 0v and 4.5V.

[bifbangpow]

Should the voltages on the socket be the same as they should have been for the chip? 

It isn't the intention to see the exact voltages that will be there with the chip present, but to check that there is no dangerous fault (dangerous for the chip). At the very least this might catch out if you fitted the socket the wrong way around, which is one of easiest mistakes no matter how experienced you are.

The scheme doesn't show pin numbers, but if that's the case, I would urge downloading the chip datasheet, if only to see the correct pin numbering.

First, the op-amps. Apply power and check for correct polarity supply voltage where the wires connect on the board.

If you first put the neg probe on the socket -V supply pin you should pick up the supply voltage on the +V pin AND do make sure it's a + reading like "8.86V" and NOT negative like "-8.86V" OR the wrong range like "8.86mV". If you don't have this right, either...
It's not actually powered due to mistake/wiring error.
You have the wrong pins.
The power to the board is reversed.
The power to the board is being shorted out.
The socket pin is not soldered.
A pcb track is broken.
... a lot of things checked for with this one simple test.
If power pins are ok. Keep the neg probe in place and see what volts is on the other pins. Op-amp circuits will usually have the reference voltage (+4.5) or less on all the input and output pins.

You also have a logic chip, the 4013.
Same check for power pins.
Look at the scheme. Only its power pin should have +9v, all other pins probably 0v either because connected to ground or nothing at all. There is a Q output to the JFET diode which might well show something between 0v and 4.5V.

Thank you.  It looks as though there was definitely in ic socket not soldered all the way in.  now that i have corrected that i at least get sound when the effect is both on and off.  however, the sound is coming through pretty clean in both scenarios.  the effect knob doesnt seem to do anything, and the on off on switch doesnt either.