HP E1Z77UT E1Z77UT#ABA manual Solving hard drive problems, Troubleshooting without diagnostics

Power LED flashes Red four times, once every second, followed by a two second pause, and the computer beeps four times. (Beeps stop after fifth iteration but LEDs continue flashing.)

Cause Solution

Power failure (power supply is overloaded).

1.If equipped with a voltage selector, check that the voltage selector, located on the rear of the power supply (some models), is set to the appropriate voltage. Proper voltage setting depends on your region.

		2.	Open the access panel and ensure the power supply
			cable is seated into the connector on the system board.
		3.	Check if a device is causing the problem by removing
			ALL attached devices (such as hard drives or optical
			drives and expansion cards). Power on the system. If the
			system enters POST, then power off and replace one
			device at a time and repeat this procedure until failure
			occurs. Replace the device that is causing the failure.
			Continue adding devices one at a time to ensure all
			devices are functioning properly.
		4.	Replace the power supply.
		5.	Replace the system board.
Solving hard drive problems
	Hard drive error occurs.
	Cause	Solution
	Hard disk has bad sectors or has failed.	1.	In Windows 7, click Start, click Computer, and right-
			click on a drive. Select Properties, and then select the
			Tools tab. Under Error-checking click Check Now.
			In Windows 8, on the Start screen type e, and then
			select File Explorer from the list of applications. In the
			left column, expand Computer, right-click on a drive,
			select Properties, and then select the Tools tab. Under
			Error checking click Check.
		2.	Use a utility to locate and block usage of bad sectors. If
			necessary, reformat the hard disk.

156 Chapter 8 Troubleshooting without diagnostics