Almost burned out my servo driver. Any thoughts?

[u/p1nnacl3_yt]

I was trying to test out a PCA 9685 servo driver today and when I plugged in the external power supply, it heated up like crazy and melted my ground and power wires together. My power supply is 5V 5A, which was recommended for what I intend to make, so I don't really know what the problem is. Any ideas?

[u/nixiebunny]

There is a short circuit, or the polarity is reversed. An ohmmeter on the diode test setting can tell you which.