Phantom PSU Doesn't Power On

Jul 28, 2018
1
0
10
I recently bought a phantom psu for my mic, when i plugged everything in i powered on psu the and the led lit up then faded away, i took a reading on a voltmeter on the plug (psu) and apparently it was only outputting 1v, its meant to output 18v, so i sent it back as faulty and bought a new one, to my surprise the new one did the same thing although it did work for a hour, is the psu meant to do this or am i super unlucky that i got 2 defective ones.
Many Thanks