Hi. I am a new member. When RS232 ports disappeared, some OEMs connected serial cables via the scart socket - a legitimate use.
The connections are:-

Scart pin 9 ground to RS232 pin 5 ground

Scart pin 10 rx to RS232 pin 3 tx

Scart pin 12 tx to RS232 pin 2 rx

This is a null modem DTE to DTE connection and applies to old SD boxes, still useful at 19.2E and 13E.
You can monitor information while the unit boots. May have to wait 15 seconds for some boxes.
Modern HD boxes will, of course use USB.