HP HB4 manual Power, State. Refer to the Upgrading and Servicing Guide for

power

Symptom	Problem	Solution
PC will not turn on	PC is not securely connected	Ensure that cables connecting the PC to the external power
and/or start.	to an external power source.	source are plugged in properly.
	Monitor is not connected or	Connect the monitor to the PC, plug it in, and turn it on.
	is not on.
	Line voltage selection switch	Set the line voltage selection switch to the correct setting for
	is not in the proper position	your country/region, or refer to the Warranty & Support
	for your country/region	Guide to contact Support.
	(115V/230V).
	Wall outlet is defective.	Test the outlet by connecting a different electrical device to
		the outlet.
	Wrong memory modules	Reinstall the old memory to return your PC to its original
	were used in an upgrade, or	state. Refer to the Upgrading and Servicing Guide for
	memory modules were	instructions.
	installed in the wrong
	location.
	Hard disk drive is damaged.	Press the Help ? button on the keyboard to open the Help &
		Support Center, or refer to the Warranty & Support Guide
		to contact Support for replacement details.
	After an upgrade or repair,	Reseat drive power, data, and power supply cables. See
	the drive power, data, or	the Upgrading and Servicing Guide for instructions.
	power supply cables may
	not be properly connected.
PC appears locked up and	PC is not working.	Press and hold the On button until the PC turns off.
won’t turn off when the On
button is pressed.
PC powered off	The unit temperature was	Unit is in an exceedingly hot environment. Let it cool down.
automatically.	exceeded.	Ensure PC air vents are not blocked and internal fan is
		running. Note that your PC may not have an internal fan.
	The unit temperature was	Replace cover or access panel, and let the PC cool down
	exceeded because the PC	before attempting to turn on power to the PC.
	was functioning with the
	cover or access panel
	removed.
	Processor or system fan has	Refer to the Warranty & Support Guide to contact Support
	failed.	for replacement details. Note that your PC may not have an
		internal fan.

troubleshooting 83