Pi3: usb 1-1-port2: over-current change - Raspberry Pi Forums

after running motioneyeos without trouble on rpi model 3 month or so, notice red power light blinking , webpage still live "can't connect camera". usb camera still works fine on computer. no usb devices connected, red power light no longer blinks, logging pi via ssh , typing 'dmesg' yields whole lot of sort of thing:

[ 763.865601] usb 1-1-port2: over-current change
[ 764.121635] usb 1-1-port2: over-current change
[ 764.377672] usb 1-1-port2: over-current change
[ 764.633703] usb 1-1-port2: over-current change
[ 764.889743] usb 1-1-port2: over-current change
[ 765.145842] usb 1-1-port2: over-current change

note nothing plugged of 4 usb ports, ethernet cable , power. i've tried swapping in known-good 6-inch long usb cable , known-good 5v2a power supply same result. after month of working fine, happens? ideas means?

found this: viewtopic.php?f=28&t=110164
casts suspicion on ap2553 chip on rpi board. love 1 of rpi hardware designers comment on finding!

with nothing connected usb port, plugged in usb power monitor , dead; there no +5v output on usb ports, hardware failure. pi running , responds via ssh. gpio pins measure +5.14 v on internal power rail, , using special cable , voltmeter measure 0.0v coming out of 4 usb ports. wonder how many other people seeing this?

u13 6-pin package marked "bk5r" (i think... small letters) , may ap2553 http://www.diodes.com/_files/datasheets/ap255x.pdf
measured u13 pin voltages:
1: 5.14 v (usb v input)
2: 0 v (gnd)
3: pulsing, 0.4v avg (enable)
4: pulsing, 0.15v avg (fault)
5: 0 v (ilim)
6: moving around near zero, 1.5 mv 4.8 mv (usb v out)

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