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Table 4-8 Diagnostic 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
indicator of bad CPU).
1. Verify that the CPU is present.
2. Reseat the CPU.
Red Power LED blinks four
times, once every second,
followed by a two-second
pause. Four beeps.
Power failure (power
supply is overloaded).
CAUTION: Internal components might be powered even when
the computer is off. To prevent damage, disconnect the computer
power cord before you remove a component.
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
times, once every second,
followed by a two-second
pause. Five beeps.
Pre-video memory error. CAUTION: Internal components might be powered even when
the computer is off. To prevent damage, disconnect the computer
power cord before you remove a component.
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
times, once every second,
followed by a two-second
pause. Six beeps.
Pre-video graphics error. CAUTION: Internal components might be powered even when
the computer is off. To prevent damage, disconnect the computer
power cord before you remove a component.
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