Sony PCG-SRX99K - Manual (Page 208)

 Make sure the battery is inserted properly and is charged.
 If the computer is in LCD (Video) Standby mode, press any key to activate the computer screen.
 If the display mode is set to external display, press and hold the Fn key while you press F7 several times.
Why don't my changes appear on the computer (LCD) screen?
You may need to refresh the computer screen. Press the Windows key and press D twice.
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