I’m pretty sure the 9V DC power supply for one of my Roku Soundbridges shouldn’t be doing that ↑↑ . This is the second unit I’ve had to replace, my other Soundbridge blowing its 5 V supply a couple of years back. This one cycles from 9.4 to 4.4 V about 5 times a second. Not very DC, but kind of lethargic for AC.
It’s hard to tell, but one of the caps inside the rather complex little Unifive wall wart may have blown. I’ve scrapped the PSU and replaced it with a beefier one. It seems that power supplies are a problem (see: 1, 2, 3, 4) on these machines, so I wonder when/if I will need to replace this one.