When Flash Drives or external USB drives are plugged in they show power and the respective LED's say they are working, but the OS never recognizes that anything has been plugged in. Checked continuity on L4605.L4600,L4615,L4610 while in circuit. Since the power is working, my assumption is that it is in the data lines. Not sure where to go on troubleshooting from here. Note: This is my first post to this forum and I am relatively new to component level repair.