Can you guess the problem I found with this circuit?
Your PC sends 5V out its USB port even if it’s turned off?
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Is that a USB microphone adapter?
Electret condenser computer mics get 5V from the mic input and you should find the same thing on the laptop's microphone connection.
When you plug-in a (condenser) mic the voltage should drop to about 2.5V and the signal "rides on top" of the DC.
...Studio condenser mics (not interchangeable with computer mics) get 48V "phantom power" from the preamp/interface/mixer. That's a "different concept" with the same basic purpose of powering a condenser mic. +48V (relative to ground) comes-in on both differential signal connections. The audio is differential and "isolated" from ground (and from the ground shield) so the preamp input doesn't "see" the (common, non-differential) DC voltage.
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Here's a hint, it's not +5V.
Nope, it's a USB to 2.1x5.5 barrel jack cable.
Unfortunately, there isn't universal agreement on polarity of power connectors.
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TELL THAT TO MY $12 LED RING I WAITED FOR 2 WEEKS TO GET 
If your LED ring has more than eight LEDs,
then you shouldn't power it from a laptop's 500mA USB port.
Leo..
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Yes I agree esp since I was using a standalone inline tester that uses full brightness. But when I did the initial non-intentionally destructive test I used a powerbank
It’s a matter of exchanging the wires 
The connector to the led tester was a female barrel jack. I didn't use the wires. There should be some indication of polarity. Colors... shape... markings... writing... anything!
Tom... 
Unfortunately it comes down to measuring the voltage at the actual barrel connector when the cable is not marked.
I've seen fairly expensive equipment that lacks polarity markings for the jack, always irritating when you need to get a replacement power supply and don't have access to the original.
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TomGeorge I didn't use that connector when I plugged in the leds. The connection was male barrel jack to female barrel jack. There's no indication on the USB-barrel jack cable as to it's polarity. Every other device I've used with a barrel jack cable (prob dozens) attached has had the opposite polarity of this one.
Yeah - when polarity is not clearly marked then you need to check… big deal…
Even when it IS marked it is a good idea to check! Wouldn't be the first time a cheap power supply has the markings wrong.
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wise words
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You're not understanding what I wrote. When I used the reverse polarity cable to test the led ring, I was not aware that it was reverse polarity because there are no markings on the CABLE to identify polarity. Please disregard the CONNECTOR you keep referring to because I did not use it when I ran the test with the led ring, ok? Please see the attached picture of my recreation of when I tested the led ring. Unfortunately I threw out the cable because I never wanted to make that mistake again for any reason.
The picture in my 1st post was a different set up I used just to show the voltage measurement. When I ran the test with the led ring there was no way to know it was reverse polarity other than measuring the voltage first. I don't know where I got the cable I had it for a very long time. All of my other barrel jack devices, probably several dozen, have center positive polarity. The cable I used was convenient because it was a USB to barrel jack converter. I made the original post just as a heads up and reminder that cables and connectors should be tested for polarity before using them.
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