IBM ThinkPad X22 Service & Troubleshooting Manual page 33

If these items are correct, have the computer serviced.
Problem: A message, "critical low-battery error," appears, and the computer
immediately turns off.
Solution: The battery power is getting low. Connect the ac adapter to the
computer, or replace the battery pack with a fully charged one.
Problem: When you take action to return from standby mode, the LCD
remains blank.
Solution: Check whether an external monitor was disconnected while the
computer was in standby mode. Do not disconnect the external monitor
while the computer is in standby mode or hibernation mode. If no external
monitor is attached when the computer resumes, the LCD remains blank
and output is not displayed. This restriction does not depend on the
resolution value.
Problem: The computer does not return from standby mode, or the standby
indicator stays on and the computer does not work.
Solution: The computer automatically enters standby or hibernation mode
when the battery is depleted. Connect the ac adapter to the computer; then
press Fn.
Problem: Your computer does not enter standby or hibernation mode.
Solution: Check whether any option has been selected that would disable
your computer from entering standby or hibernation mode.
Problem: The computer does not enter standby mode as set by the timer
under Windows 95 or Windows NT.
Solution:
v For Windows 95:
The generic CD-ROM or DVD-ROM driver for Windows 95 accesses the
internal CD-ROM or DVD-ROM drive every 3 seconds to see whether a
CD-ROM is inserted there. This prevents your computer from entering
standby mode even after a timeout. To enable the computer to enter
standby mode, do the following:
1. Click Start.
2. Move the cursor to Settings and Control Panel.
3. Click Control Panel, and then double-click System.
4. Click the Device Manager tab.
Chapter 2. Solving computer problems
21