Can turn on over GPIO but USB doesn't work [solved]

[briansallee]

Hello all,
First a disclaimer that I am very new to DIY electronics (Software Developer with man many years computer experience) but this making stuff and soldering are new to me so please forgive my apparent ignorance and what are bound to be annoyingly noobish questions   So this is my first time with a soldering iron and I am reading and learning as I go!  Exciting stuff. 

I just put together my ATXRaspi, and wired it to an uniluminated SPST NO Momentary switch.  My multi-meter with probes on the end of the terminals set to continuity beeps when I push the switch.  I also have continuity through the wires, and also on the header block when the wires are connected and the switch is pushed.  Point being I believe the switch to be fine.

However after applying input power to ATX Raspi and output power over the USB to the RPI3, a push of the button does zip.
However if I go from the +/- power header to pins 2/6 on the GPIO block the ATXRaspi powers up the PI with a button press.

So great on the one hand - I have a workable solution, just don't use USB.  However I want it to work the way I wanted to do it   And I want to learn the best way to troubleshoot this.
I believe my soldering to be crude and hamfisted, but I don't see any visible mistakes with the USB header. 

What would you recommend for troubleshooting the USB header?  Should I check for 5v on the first pin when the switch is depressed, does it matter which probe is used the red or common?  And this might be way stupid - but how do you have enough hands to hold a probe in the socket and work the switch etc all at once?  Those stupid probes seem to have the worst shape for staying put and are difficult to get them to stay posed so you can manipulate other things.  I'm combing youtube to see how other people do such things and it looks like alligator clips are useful, but I don't see how you could use one inside a Type A connector.  What else should I be doing to try and figure out why the power over USB is a no go?

Thanks in advance for your advice!
Brian

[sparky]

Brian,

Looking at the picture it appears the far left pin (VCC) of the USB connector could use some attention.  I would re-solder that pin and then retry. 

Also; not related to your problem but I would add some solder to the 2 large pins ( usb case/ cable shield) which gives the connector a lot of strength when inserting or removing your cable.  Your shutdown pin could also use some more solder.   

[perky]

Personally I'd do more learning on how to solder correctly, you'll be chasing your tail forever trying to fix things if they're not soldered properly. Plenty of on-line tutorials out there.
Mark.

[briansallee]

Okay so I desoldered the USB header and resoldered it, also soldered the  outside pins for stability (Thanks @Sparky) and lo and behold it worked! 

@Perky - I think it's gonna take a lot of practice before I have the skill and dexterity to do this well - also think maybe I need a smaller iron as the one I have is huge and clunky.  I've been watching a bunch on youtube, there is no shortage that's for sure.  It's still a work in progesss

Thanks much for the help and advice.   

[sparky]

That's great!  The ole saying, practice makes perfect.  Felix sells a lot of great toys to practice with... 

Edit: Definitely get yourself a good, temperature controlled soldering iron along with some good quality solder, it makes a huge difference.

[perky]

I did a lot of research into soldering irons and tips. I ended up with a Hakko FX-888 with Plato HS-8175 tips which is an excellent combination. Hakko now do a digital version instead, FX-888D, and the HS-8175 have been discontinued but the Hakko equivalent version is 900M-T-S4. Anyway, this is a bit OT for this thread...
Mark.
Edit: The 900M-T-S4 tip is itself superceeded by T18-S4! Shows how quickly things move. The point is that the tip should IMO be a short, fat conical shape with a very fine point at the end, this is best for maximum heat transfer and is best for general purpose use (SMD and throughhole).

[briansallee]

Thanks Mark!  Looks like super nice kit.  Think I'll ask Santa for these, and if he doesn't come through maybe I'll just have to treat myself.