Hi Guys,
I recently purchased this: https://core-electronics.com.au/usb-micro-b-male-plug-to-5-pin-terminal-block.html
Following the pin guide below, I connected my positive to V+ and negative to GND per the image also below.
- E – Pin 1 (V+)
- D – Pin 2 (D-)
- C – Pin 3 (D+)
- B – Pin 4 (ID)
- A – Pin 5 (GND)
I am connecting the wiring into a variable step down converter from 12v to 5.1V.
As soon as I turn the power on the step down converter cuts all load to the Raspberry Pi Zero the Micro USB head is connected into.
When I terminate a proprietary Micro USB that I cut and exposed the black/red wiring into the same step down converter it works perfectly fine.
I only need this to power the Pi (no data transfer of course).
Your help would be much appreciated.
Thanks!
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Hi Samuil
About all that could go wrong here is the connections are reversed. Although they look correct according to the markings I don’t think this would be the first time this sort of mistake has been made. It may pay to somehow do a continuity check to be sure.
The fact that the converter is shutting down possibly due to reverse connection protection suggests this. Also the fact that all is OK if this adaptor not used.
Cheers Bob
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Hi Robert,
Thanks for your reply!
I actually did swap out the red and black wiring just in case, I just didn’t mention it as I know it isn’t something you should normally do 
but at the end of the day I knew my DC-DC converter would prevent any damage to the Pi.
Having said that, any other ideas?
I was really hoping to use this than butchering cables constantly!
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Hi Samuil, which micro USB port you’re using? The power port that is on the right, when you’re facing the connectors side of the board? The other one is a dual mode (data and power).
Also, if you have a multimeter, check the continuity, also if there are any wire pieces (strands) inside the adapter, which shorts out when connected. Looks like it is an electrical issue.
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Hi mate,
I am using the standard power port on the Pi Zero (not the one adjacent to it).
I will test for continuity for sure and if there is any shorts and report back.
Thanks again
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You’re welcome, Samuil.
Since the cannibalized micro USB works well, there is no issue with Pi connector, which is a big relief. The step-down power supply also works well with the cannibalized micro USB, so the issue is not with the power supply either. That isolates the issue to the add-on connector.
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You should check the pinout of a micro b connector on wikipedia then just check to see what’s what.
If you can’t get your multimeter probe in there a trick I use sometimes is to just strip some stranded wire - tape one end to your meter probe so it makes good contact, and then separate the strands at the other end and use ansingle atrand as a multimeter probe.
Obviously only really good for checking continuity or rough measurements.
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Hi mate,
I just checked for continuity and there is definitely no continuity. I used terminal blocks, exposed 18awg wire taped to the multi-meter pins and even tried directly on the Micro USB to USB terminal block slots and still only receiving a value of 1 as opposed to 0 or something close to 0.
Looks like a faulty item to me.
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Thank you Oliver, as you can see I used your method of ensuring good contact when checking for continuity and had no luck - looks like a faulty item unfortunately. 
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Yes, it is always a pain to troubleshoot.
Question: Since you already cannibalized one micro USB, why don’t you just solder the two wires from the power supply, insulated with heat shrink tubing and use it?
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Hi Samuil
'1" is a strange result. You probably will never read “0” as the leads have some resistance. 0.1Ω to even 0.4Ω would be pretty normal. “1” could be the leads coupled with a less than perfect connection. If it was actually open circuit I would expect “OL” (overload or over range) or some other indication of a value outside the range of the meter. Maybe you need to refine the measurement technique.
Cheers Bob
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That is what I currently do, but because I deploy quite a few Pi’s every week and its becoming expensive to buy the cable and cut off one end off. I was hoping I could get this to avoid the extra costs with buying a full cable and use my own wiring which I have bulk of and want to put it to use 
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I bought one of those for exactly the same reason and it works very well.
Pic to prove it. Maybe you have a doggy one.
Regards
Jim
PS Black resistance 0.3 Ohm, red 0.4 ohm. About what I would expect.
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Looks like your connections are the same as @Samuil155885 's, so doesn’t look like that should be the problem (although I know sometimes with cheap parts like this suppliers can do the old switcheroo on retailers if they find a cheaper manufacturer and no-one realises until they go to use it).
If whatever you’re powering is reverse voltage protected, it might be worth flipping your connections - though the ground should connect through to the connector housing anyway I believe.
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