[donbrew]

It is a ATX power supply connected via gpio pins.  I have a VOM hooked up to it never goes below 5.05V.
This is the fourth PSU I have tried.

There is this warning in dmesg:  

this is from LE, but the same one popped up at a different time in OSMC.  It does not affect LE.
[    6.290414] brcmfmac: power management disabled
[    7.150430] IPv6: ADDRCONF(NETDEV_CHANGE): wlan0: link becomes ready
[   19.251672] Voltage normalised (0x00000000)
[   21.385028] Under-voltage detected! (0x00050005)
[   36.321720] Voltage normalised (0x00000000)
[   38.451770] Under-voltage detected! (0x00050005)
[   59.785137] Voltage normalised (0x00000000)