Universal Serial Bus (Usb) Cannot Be Used Normally - Brother PR600II Service Manual

Failure Investigation for Electronic Parts Universal serial bus (USB) cannot be used normally.
Is the USB device firmly connected?
When the USB device is replaced with
a new one, dose it work correctly?
5 - 20
Universal serial bus (USB) cannot
be used normally.
Y
N
Change panel PCB.
N
Connect it properly.
Y
Replace the USB device.