Brand: FUJITSU
Category: Computers
Document Type: Manual
Language: EN
Available Languages: EN , ES
Manual for LIFEBOOK U939
Uploaded: Nov. 21, 2025, 6:06 p.m.
Manual Publish Date: 2019-01-01
Warranty Information
Your LIFEBOOK notebook is backed by a Fujitsu International Limited Warranty.
Getting Started: Ensure the device is connected to AC power. Follow on-screen instructions for initial setup. The battery must be charged for portable use.
Daily Operation: Use the keyboard and touchpad for navigation. Utilize hotkeys for quick functions. Connect external devices via available ports. Refer to the "Working with the notebook" section for detailed operations.
Power Management: Switch off the notebook when not in use. Utilize energy-saving functions to prolong battery life.
Troubleshooting and error codes
| Problem | Possible Cause | Possible Solution |
| Unavailable network connection | Incorrect network name (SSID) or network key | Ad hoc connection: Verify network names (SSID's) and keys (WEP) are identical. Access Point (Infrastructure) connection: Set network name (SSID) and network key to match the access point. Set Network Authentication value identically to the Access Point. |
| Weak received signal strength and/or link quality | N/A | Ad hoc connection: Shorten distance or remove obstacles. Access Point (Infrastructure) connection: Shorten distance or remove obstacles. |
| Unavailable network connection (continued) | The WLAN device was deactivated or is disabled | Check if the wireless switch is turned On. Go to Start > Control Panel > Windows Mobility Center. Turn wireless on if it's off. |
| Unavailable network connection (continued) | The computer to be connected is turned off | Check if the computer to be connected is turned ON. |
| Unavailable network connection (continued) | Incorrectly configured network settings | Recheck network settings configuration. |
| Unavailable network connection (continued) | RF interference from Access Points or other wireless networks | Change the channel of your Access Point to avoid overlapping RF channels. |
| Unavailable network connection (continued) | Wireless network authentication has failed | Re-check Network Authentication, Encryption, and Security settings. |
| Unavailable network connection (continued) | Incorrect IP address configuration | Contact your network administrator for correct settings (applies to static IP addresses). |