Dell Inspiron 1558 line in/Mic/Phone socket

[#1]

The aforementioned machine, has only one phone socket.... and when I plugged in my phones before, it used to show a pop=up window asking what had been plugged in...and then the software would switch it to whatever use was required..
I don`t know what happened.. ....  maybe the bluetooth has stopped it ... but now I can`t use a mic or line in .. only plug in phones.. 
Anyone got any ideas ? 

[#2]

did you try Hardware manager , see if its enabled .  or update drivers ?

[#3]

Sounds like a driver issue, check the driver from the Dell site.

[#4]

Nothing showing in "Device Manager"    ...
(mic is enabled)..
Done all the updates that Dell had for my machine.. ( latest updates only a couple of days old)..
Re-booted and still no notification/choice pop-up window.
However... weirdly.... I have a radio that I take signals from and decode them using another program... and print it on screen through the "line in/mic" socket... ( which as mentioned is also the same socket for phones)..
I have two radios, and have made a double splitter box... so I can choose the line out  output from either radio and channel it to the laptop... I can also listen using same splitter box) to either of the radio`s by switching the "audio" output to phones plugged into the splitter box...
So... with an inline connector from the splitter box, I can pass the line out signal to the laptop...
. However, If I remove the phones from the other socket ( the audio output)on the radio splitter box,  the signal disappears from the line in....
(if I put a splitter on the laptop end I can faintly hear the sig by plugging in the phones to that splitter)... so the signal level is significantly lower. !.. not enough to be decoded by the laptop.
Prior to the present problem... it mattered not whether phones were plugged into the radio splitter box... the signal was always "good" at the laptop.
Perhaps I shall have to contact Dell direct, and see if there is some other driver that I need to replace/repair....

[#5]

Just had a quick google   has your laptop have 2 headphone sockets lefthand side ??  and IDT HD sound ?
Most people had to unistall driver and reinstall to get it working

[#6]

Erm .... no....  the clue is in the first line of my original  post  ! !   

[#7]

Dooooooh    my senior moment