Acquired a 4-pole TRRS connector for the RPi 2 B 3.5mm analogue audio/video socket as depicted with
The RCA plugs on the other end of the cable are connected to a SCART adapter, which is then connected to a Philips analogue TV.
Have setup in "/boot/config.txt" the configuration variable "sdtv_mode=2" to denote a PAL supporting TV set.
However, no image apart from noise on the screen 
I'm sure I've followed the instructons for the right cable as outlined in a post of the Raspberry Pi forum.
Have you checked the Scart pins to see if they are sitting correctly?, is there a switch on the Scart for input/output switching?. 
The SCART PINs are correct for RCA input supporting as input: Video (yellow coloured plug), Audio-Left (white coloured plug) and Audio-Right (red coloured plug).
Plugging the same 4-pole TRRS jack into a multimedia disk of mine, I do get the picture and sound on the PAL TV when playing back videos.
I’m now following the outlines given with the article “Understanding TRRS and Audio Jacks” to better understand the situation I’m facing currently…
I can’t help you further as I don’t have the same set-up as you sorry!. 
I have updated my orignal post with the real picture of my plugs and SCART adapter. From what I undertsand there seem to be different TRRS standards as depicted with
and the one for the Raspberry Pi 2 B ought to have the following break out leads:
This breakout lead is supposed to be called “Zune” (as per above picture) or “CTIA/Apple” as per “Understanding TRRS and Audio Jacks” guide.
Seems like I have to measure each of the cable ends to determine actual wiring of poles… 
The nearest I have to that cable is for a Matricom streaming box but the picture is really bad on my HD TV!.
