HP Z420 D3J34UT#ABA, Z220 F1J90UAABA Device that is causing the failure. Continue adding devices

Table 4-8Diagnostic lights and audible codes (continued)

Activity Possible cause Recommended action

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

CPU not installed (not an 1. Verify that the CPU is present.

indicator of bad CPU).

2. Reseat the CPU.

Red Power LED blinks four	Power failure (power	CAUTION:		Internal components might be powered even when
times, once every second,	supply is overloaded).	the computer is off. To prevent damage, disconnect the computer
followed by a two-second		power cord before you remove a component.
pause. Four beeps.		1.	Open the access panel and ensure that all power
			connections 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 computer. 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.
Red Power LED blinks five	Pre-video memory error.	CAUTION:		Internal components might be powered even when
times, once every second,		the computer is off. To prevent damage, disconnect the computer
followed by a two-second		power 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
times, once every second,		the computer is off. To prevent damage, disconnect the computer
followed by a two-second		power 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.	Confirm the graphics card is in the appropriate slot (PCIe
			x16).
		4.	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 computer model for detailed information on clearing CMOS.

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

150 Chapter 4 Diagnostics and troubleshooting