Summary: Audio and/or Video distortion may occur when using the keyboard to adjust the display brightness when playing multimedia content (online or stored locally).
If you encounter a situation where the audio on your Dell portable system becomes distorted (cracks, pops, drops etc.) or the video freezes momentarily or stutters when you attempt to adjust using the keyboard shortcut keys, this is caused by making changes to the LCD screen brightness during playback.
Adjusting the display brightness via the keyboard generates multiple processor interrupts and these interrupts can affect the playback of video or audio on the system regardless of the multimedia source.
This effect may be more evident on some system configurations than it is on others.
This issue is not a fault, but simply a limitation of the operating system.
The solution is to not manually adjust the display brightness during playback. The issue only occurs when the keyboard function key shortcut is pressed and held. Momentary function key adjustments (one second pause between key presses) to adjust the brightness will not cause this distortion.
If a brightness change is needed, it is suggested that you pause the playback, make you brightness adjustment then resume the playback or make adjustments with momentary key presses.