Unexpected Upcycling: building a new server from an OLD server! IBM System X3400

I wanted to build a tower server with lots of hot-swap SAS disk bays, but case options are few and far between. However, with some creativity and hackery, one can retrofit ATX parts into semi-proprietary IBM System X (now known as Lenovo ThinkSystem/ThinkServer) Tower Servers. These machines are cheap (i bought mine for 60GBP incl. shipping) and spacious, and are therefore well suited for customization and modernization. The generous number of 3x5.25" bays and 8x hot-swappable 3.5" SAS/SATA bays on this machine was particularly attractive to me.

This video demonstrates the conversion of an IBM System X3400 to allow the use of standard modern components - an ATX PSU and motherboard - as well as modifying the electric wiring for the proprietary SAS backplane as well as the front USB and power button/led panels. This conversion is an excellent option for those looking to build a custom NAS.

Thanks to ‪@victorbart‬ for your x3400 teardown video - the details provided there allowed me to look at the case and parts in great detail, giving me confidence that my project had at least some chance of success :)

Thanks to Grant Emsley at www.emsley.ca for providing the SAS backplane pinout - without having it in advance I might not have opted in to modify this specific machine.

Some of the tools used in this video:
Dremel 4250 Rotary Tool Kit (https://www.amazon.co.uk/dp/B0949FBVR...)
Cheap and good tweezer set (https://www.amazon.co.uk/gp/product/B...)
UNI-T UT139C Digital Multimeter (https://www.amazon.co.uk/dp/B08FCD7R9...)
Wiha Plier Set (https://www.amazon.co.uk/dp/B001J71KC...)