44 CHAPTER 4 LOCATING THE PROBLEM
USB symptoms
Symptom Corrective Procedure
• USB device does not function 1. Check that the USB device is detected in Windows Device
Manager.
2. Reinstall the USB device driver.
3. Replace the mainboard.
Peripheral-device symptoms
Symptom Corrective Procedure
• USB ports do not work
• COM ports do not work
1. Reseat the I/O cable.
2. Reinstall the drivers.
3. Replace the mainboard.
Boot symptoms
Symptom Corrective Procedure
• System continually reboots on
power up
1. Restore the BIOS defaults.
2. Remove all I/O device drivers, then reinstall the drivers one
by one.
3. Reseat the SATA cable.
4. Reseat the memory card.
5. Reseat the power adapter.
6. Replace the mainboard.