I think you’re on the right lines, I tried the iFi PSU with my 3B+ and DigiOne Sig, and it was definately not a happy bunny.
I found a PSU with a 3A capability, and that seems to be happy with 3B+, IQAudio DAC Pro, and the 7 inch screen. I think it was an Amazon jobbie.
I found a PSU with a 3A capability, and that seems to be happy with 3B+, IQAudio DAC Pro, and the 7 inch screen. I think it was an Amazon jobbie.