SC4020 serial cable pinout / diagram

To not waste anyone's time, i hope you find this post before spending hours debugging the stupid serial cable.

I'd like to first state that there was no lack of space, or any other issue that should have led Dells engineer team to use the most akward, unavailable serial interface of all times. I hope the person who made this call is deeply regretting it.

Nowdays it's pretty much impossible to find the OEM cable, and as i've learnt the ones on amazon and ebay all have another pinout.

The pinout required is:

DB9 Pin5 to 3.5mm jack "ground", which is the closest of the 3 areas to the plastic connector.

DB9 Pin2 to 3.5mm jack "middle".

DB9 Pin3 to 3.55mm jack "tip".

I ended up simply buying one on amazon, cutting the cable in the middle, and swapping the TX and RX (in my case, Red and White cables) to get the correct pinout.