HP vs17c monitor w/built-in stereo speakers plays no sounds

[KNRover]

Am renovating an old HP Pavilion desktop for disadvantaged kids. Has an HP vs17c monitor whose speakers don't work. Have tried changing Win XP sound scheme, Realtek setting, analog settings using sound buttons on side of monitor, etc. Nothing works. What am I missing that would bring them alive!?

 

[Lutfij]

According to this installation guide there should be a green 3.5mm audio/stereo cable running from the back of your desktop(from the sound cards output which will also be a green ringed port) up to the back of your monitor at the base of the latter will be a port similar to that found off the back of your system.

Hope this helps.