Fried my gpio pins?

Question

I might have fried my gpio pins. I have a pie 3b with Hyperion installed and I’m trying to use it to run a set of ws2812 led lights. The led lights are running off of a 5v 8amp power supply and the pi is running off of a cell phone charging cable. Anyways I ran a jumper wire from gpio 18 to the data in wire on the led and it lite up but was just producing random colors and the lights would flicker off and on sporadically. After doing a little research I thought that maybe I needed to hook up a common ground between the two so I used a jumper wire between the gnd on the led and pin 6 on the pi and now I can’t get the led to light up at all. Did I toast the gpio pins? I don’t currently have a volt meter but plan on getting one in the next few days. Can I run a test with the volt meter between gpio 18 and one of the ground pins to see if I shorted it out?

Answer 1

No one can say. You need to perform some tests.

Whenever you connect any device to the Pi you MUST connect the Gnd FIRST. (For the pedants there are a few exceptions where another pin is used as common).

If you connected the Gnd to a live circuit there is the possibility you did other damage.

Most of these LED strips NEED a 5 V logic signal to drive them - usually via a level converter.
The fact that it does not work with a 3.3 V logic signal does not necessarily indicate a problem.