HP Z400 Maintenance And Service Manual page 209

Table 6-8 Diagnostic lights and audible codes (continued)
Activity
Red Power LED blinks four
times, once every second,
followed by a two-second
pause. Four beeps.
Red Power LED blinks five
times, once every second,
followed by a two-second
pause. Five beeps.
Red Power LED blinks six
times, once every second,
followed by a two-second
pause. Six beeps.
ENWW
Possible cause
Power failure (power supply
is overloaded)
Pre-video memory error
Pre-video graphics error.
Recommended action
CAUTION:
Internal components might be powered even when the
workstation is off. To prevent damage, disconnect the workstation power
cord before you remove a component.
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 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.
3. (For computers with a BIST LED on the rear panel) Check the power
supply functionality:
a.
Disconnect the AC power.
b.
Disconnect ALL internal power supply cables.
c. Plug in the AC power.
d. Power on the computer.
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.
CAUTION:
Internal components might be powered even when the
workstation is off. To prevent damage, disconnect the workstation 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.
CAUTION: Internal components might be powered even when the
workstation is off. To prevent damage, disconnect the workstation power
cord before you remove a component.
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.
Diagnostic codes and errors
197