HP Z VR Backpack G1 - Mechanical; Fan Error Message - 90 B

Mechanical
Fan error message - 90B
Items Procedures
Symptoms
Fan error 90B at boot
CAUTION: May lead to system
shutdown, data loss or possible system
damage.
Possible causes
Defective fan; out-of-date BIOS.
●
The system fan is not spinning or not spinning properly (loose connection, fan is stuck or
defective).
●
The temperature inside the case is too high, and the fan cannot spin fast enough to
remove the heat due to an obstruction to air ow.
Troubleshooting steps
General actions
1. Update BIOS and drivers (4. Update BIOS and drivers on page 34) or reset BIOS to default.
BIOS may implement new fan characteristics and updates for other components.
2. Perform a hard reset (8. Hard reset on page 41). Performing a hard reset can reset
recorded thermal values in memory.
Thermal-related issue
1. Verify thermal condition:
a. Check fan and connection. Reseat fan cable.
b. Be sure that no obstructions or dust are in heat sink fan, n, or vent.
c. Test fan using HP PC Hardware Diagnostics (UEFI) tool (6. HP Hardware Diagnostics
and Tools on page 35). Be sure that the fan is not producing loud noise and that fan
blades spin correctly.
d. Test with a veried working fan.
e. Remove old thermal compound and pads, and replace properly with new pads.
2. Verify thermal solution
▲ Use Thermal Monitor tool (available only to authorized service providers/
technicians) to run stress test (processor and GPU) and verify that thermal sensors
are within limits after thermal condition is serviced.
Note BIOS currently omits fan presence detection to shorten boot time delay less than four seconds.
Therefore, the fan error is generated based on previous boot to operating system that found
system fan error.
Fan often is part of thermal solution, including heat sink, n/ muer, and thermal grease. Fan
replacement requires reboot and fan function verication using HP PC Hardware Diagnostics
(UEFI) tool.
80 Chapter 7 Troubleshooting guide