No/Intermittent Audio XU4 Pulstar

[calculatedkaos]

I have an odd sound issue with my XU4. I have intro sound and sound with older systems (SNES and older... ish) but N64, PSX, PSP, Dreamcast all have no audio, my menu has no audio, and the preview videos have no audio. This seems to be intermittent, however. I can't figure out what causes it to come and go. It stops and then one day I will boot it up and it will start working again. This is through HDMI.