HP Z400 H2D81US, VA799UT 799UT#ABA manual Activity Possible cause Recommended action

Table 6-8Diagnostic lights and audible codes (continued)

Activity	Possible cause			Recommended action
Red Power LED blinks four	Power failure (power supply	CAUTION:		Internal components might be powered even when the
times, once every second,	is overloaded)	workstation is off. To prevent damage, disconnect the workstation power
followed by a two-second		cord before you remove a component.
pause. Four beeps.		1.	Open the access panel and ensure that all power connections (24-
			pin Main, 4-pin CPU) are secure on the system board.
		2.	Check if a device is causing the problem by removing all attached
			devices (such as hard, diskette, or optical disk drives, and expansion
			cards.) Power on the workstation. If the system enters the POST,
			power off and replace one device at a time; 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.
		3.	Check the power supply functionality.
		a. Disconnect the AC power.
		b. Disconnect ALL internal power supply cables.
		c. Plug in the AC power.
		If the power supply fan spins and the BIST** LED lights, the power supply
		is functional. The problem might be on the system board. Contact HP for
		assistance.
		If the power supply fan does not spin or the BIST** LED does not light, the
		problem might be in the power supply. Contact HP for assistance.
Red Power LED blinks five	Pre-video memory error	CAUTION:		Internal components might be powered even when the
times, once every second,		workstation is off. To prevent damage, disconnect the workstation power
followed by a two-second		cord before you remove a component.
pause. Five beeps.		1.	Reseat DIMMs.
		2.	Replace DIMMs one at a time to isolate faulty module.
		3.	Replace third-party memory with HP memory.
		4.	The problem might be on the system board. Contact HP for
			assistance.
Red Power LED blinks six	Pre-video graphics error.	CAUTION:		Internal components might be powered even when the
times, once every second,		workstation is off. To prevent damage, disconnect the workstation power
followed by a two-second		cord before you remove a component.
pause. Six beeps.		1.	Reseat the graphics card.
		2.	Verify the graphics auxiliary power cable is connected (if applicable).
		3.	The problem might be on the graphics card. Contact HP for
			assistance.

Red Power LED blinks seven times, once every second, followed by a two- second pause. Seven beeps.

System board failure (ROM detected failure prior to video).

1.Clear CMOS.

NOTE: Refer to the Maintenance and Service Guide for the workstation model for detailed information on clearing CMOS.

2.The problem might be on the system board. Contact HP for assistance.

136 Chapter 6 Diagnostics and troubleshooting ENWW