Table 6-5
System diagnostics failure codes and user actions (continued)
Test description
Failure description
Error
code
Suggested user actions
Chassis Fan Not
Detected (Front)
Fan
Fan not operating correctly
90B
The system fan may be malfunctioning. Replace the fan.
System Temperature
Thermal shutdown has
occurred.
90D
The System BIOS has detected your machine was previously shut
down to avoid overheating. Overheating may occur if the cooling
vents are blocked or the operating temperature exceeds the
system specifications. The machine should return to normal
operation once the situation is resolved.
Fan Speed Failure
The system has detected
that a cooling fan may not
be working properly.
90F
Try the following:
●
Press
Enter
to clear the message and boot to the Windows
desktop.
●
Shut down Windows.
●
Clean the exterior of the vents to remove dust build-up
while the computer is Off.
●
Check for a BIOS update.
Power Good (Troubleshooting) lights
HP has added troubleshooting power lights to mobile workstations to help troubleshoot power-on issues. The
lights indicate when the system board power rails are unstable and/or the system needs a hardware reset.
Power good lights
Power good lights, HP ZBook Studio G4 model location
Troubleshooting lights diagram
General troubleshooting steps
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