Brilliant thanks for confirming... Thought it was standard what SATA connector. I've been inside baby times cleaning, and upgrading the drives.  
So I have my ageing (but still booting in 10 seconds flat and amazing) XPS One 2720 running Windows 11 just fine. I haven't used the BD/DVD Writer drive in absolutely ages, but I wanted to burn a DVD image tonight - it shows in device manager, reports no issues etc. However, when I pop ANY type of disc, be is CD, DVD, DVD+r or DVD+rw, it takes it in, spins it a bit, then spits it out a few seconds later. It doesn't throw any error, and doesn't bring any drive letter up in Windows explorer!! I can't think what could be wrong with it. It's an HL-DT-STDVDRWBD_CA40N with Firmware A102. If it has simply died - is it possible to throw ANY drive in there that is pin compatible? Slot loading of course to match! Thanks
XPS One 2720, BD drive failure