Sudden USB problem

I've been running an Asus P8Z77-V motherboard on a homebuilt PC for 3 years with no issues. Suddenly today I have USB connection problems with my flight controllers. I have several items plugged into USB: CH yoke, CH pedals, CH throttle quadrant, Logitech joystick, Logitech mouse, and two external drives.  The flight controllers suddenly have connection problems, with the USB connection cutting in and out (making that Windows soft "dong" USB connection sound).  This happens plugging different controllers into different ports - all four controllers, or just one. 

However the mouse connection remains steady, and plugging a USB thumb drive into a port works fine also. It's almost as if the flight controllers, which presumably require more power to operate, suddenly don't have the steady power they did before.  However the two external drives (one with its own power plug, but the other without) have no connection issues.

No Windows updates were installed before this happened.  There are two notable events in the last 24 hours I recall: (a) the watercooled i2700 processor was running at 80 degrees (hot day here; Tjmax=98 deg), and (b) I somehow installed a malware "SmartSaver +15" program which I had to remove with MalAware.

I've not yet tried updating BIOS or anything else as I can't imagine what would bring on a sudden failure like this, thought I'd start by seeing if this issue rings a bell with anyone