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2,812 Tutorials

How to troubleshoot USB devices

Banish those USB blues

7. If random dropouts still occur, try temporarily unplugging all non-essential devices. A USB port provides only 2.5W of power (500mA at 5V). Sometimes that either isn’t enough or the motherboard can’t reliably supply it – especially if you’re running multiple high-power devices without dedicated power supplies.

Step 7

Step 7

8. The best solution to power-related problems is to buy a powered hub. Most hubs are ‘bus-powered’, drawing their power from the USB port they’re plugged into. What you’re after is a ‘self-powered’ hub, drawing its power from the mains. Previously erratic devices will often then operate faultlessly.

Step 8

Step 8

9. Your hub won’t need a driver: just plug and play. It won’t always need the mains adaptor, either. It will work quite happily in bus-powered mode when you’re using low-power devices. Also, if your PC has no front-mounted ports, your hub should put an end to ferreting under your desk to attach devices.

Step 9

Step 9

10. Using a self-powered hub in bus-powered mode (or just a plain bus-powered hub) carries a caveat. As the ports are fed by a single host, they share a single 2.5W output. One-fifth (100mA at 5V) is used by the host, leaving only 2W (400mA at 5V). Some devices might now refuse to function.

Step 10

Step 10

>>NEXT PAGE: HOW TO INSTALL A USB 2.0 PCI CARD

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