The System Management Controller(SMC) has an another system reset that adds to the PRAM, four finger, Option+Command+P+R reset. Source: The SMC (system management controller) is a chip on Intel-based Macs that manages important physical components of your computer. The SMC controls various hardware functions like cooling fans, status lights, system performance, and power supply. . . . shut down your Mac . . . Press the right Shift, the left Option key, and the left Control key and hold for 7 seconds. Then, press and hold the power button. BACKGROUND: My USB hubs failed so I bought a small USB hub, "surf ONN," from WalMart. Plugging it into the MacBook USB-C port adding a thumb drive would work only once. Switching the hub to the second port, again, it would work once. Thereafter neither port worked. Eventually, I learned about the SMC reset which makes sense. The MacBook apparently was stopping power to the hub which of course meant no device would work. I will re-enable the startup programs and see if this problem comes back. Hopefully, not now I know how to reset SMC. Bob Wilson
Welcome to life in the "walled garden." I threw my CFO into the garden so that she could interoperate with others in that ecosphere, but MY home 'PC's are still a (work) 'PC' and a 'rescue' Dell. I keep a few rescue Droids in the yard because I still understand how to do a few things unsupervised......
Well there was a twist: USB failures mean back out to an earlier version Unable to backup using USB So I did the following: Bought a USB storage disk, 5 TB Used backup MacBook to format disk Established an ethernet link On the primary machine, accessed the storage disk on the backup MacBook Started backup software using the backup MacBook, storage disk. The backup is already 10% done and marching along. If it reaches 100%, mission accomplished. Bob Wilson
