15.01.2024 Views

CompTIA A+ Certification All-in-One Exam Guide

  • No tags were found...

You also want an ePaper? Increase the reach of your titles

YUMPU automatically turns print PDFs into web optimized ePapers that Google loves.

USB Configuration

The biggest troubleshooting challenge you encounter with USB is a direct

result of its widespread adoption and ease of use. Pretty much every modern

PC comes with multiple USB ports, and anyone can easily pick up a cool new

USB device at the local computer store. The problems arise when all of this

USB installation activity gets out of control, with too many devices using the

wrong types of ports or pulling too much power. Happily, by following a few

easy steps, you can avoid or eliminate these issues.

Windows, Linux, and macOS include many built-in drivers for USB

devices. You can count on the OSs to recognize keyboards, mice, and other

basic devices with their built-in drivers. Just be aware that if your new mouse

or keyboard has some extra buttons, the default USB drivers might not

support them. To be sure I’m not missing any added functionality, I always

install the driver that comes with the device or an updated one downloaded

from the manufacturer’s Web site.

The last and toughest issue is power. A mismatch between available and

required power for USB devices results in scary error codes and can result in

nonfunctioning or malfunctioning USB devices. If you’re pulling too much

power, you must disconnect devices off that root hub until the error goes

away. Install an add-in USB expansion card if you need to use more devices

than your current USB hub supports.

There’s one more problem with USB power: sometimes USB devices go

to sleep and won’t wake up. Actually, the system is telling them to sleep to

save power. You should suspect this problem if you try to access a USB

device that was working earlier but that suddenly no longer appears in Device

Manager. To fix this, head to Device Manager to inspect the hub’s Properties,

then open the Power Management tab and uncheck the Allow the computer to

turn off this device to save power checkbox, as shown in Figure 10-12.

Hooray! Your file is uploaded and ready to be published.

Saved successfully!

Ooh no, something went wrong!