Noise that sometimes disappears on power off/on cycle

Hello,

I'm getting some 40dB excess noise (hiss) on my ADAU1445 board which when turned off and on again several times, often disappears.

With the USBi connected, much the same thing happens with hitting link-compile-download several times makes things go quiet.

The noise appears to stem from the ADC.

Any ideas on what to look at please? Happy to send sigmastudio project over.

Thanks,

Alex.

Audio Signal Processors

adau1445

SigmaDSP Audio Processors