Is the rear, green, audio socket on Dells for a jackplug or a phono?

Computers normally use 3.5mm three-contact "stereo" jack connections. Some may also have a single phono [RCA] socket but that is normally for digital S/PDIF audio rather than analog connections. Some have an optical port as well or instead of the phono.


The bank of colour coded audio sockets will be 3.5mm jack.
The auto-detect system may rely on whatever is plugged in having electrical resistance in a certain range. An unconnected lead or eg. one feeding a high-impedance input on an amplifier may not register correctly.

Something like a pair of headphones should definitely trigger auto-detect if it is working.

That system also relies on the correct audio drivers being installed and being set for automatic selection. Missing or incorrect/incomplete drivers, or if the audio has been set for manual selection, can stop it working.

A motherboard with auto detect should work regardless of what audio socket you plug eg. speakers in to, you just confirm what you connected in the popup.

It's also possible the speaker socket has been damaged at some point.


Not all motherboard support auto functions.
Simpler or older ones may have permanently set functions for each socket so there are no popups; in that case you would get audio out from the green socket when something appropriate is connected _and_ you select that as the output connection in Windows control panel > Sound settings. [Plus having the correct drivers installed].

It's for an amplified speaker to be plugged into or a set of headphones don't plug a big speaker into it and expect the speakers to work

green is 3.5mm for headphones or speakers that do not need power(less than 2 watts) there havnt been phono sockets on pc's ever that i can remember except perhaps for a TV Tuner/Capture card. you need some external hardware to do that.

see owner's manual for that exact model -- it's online