$30 for a 3D printed 2.5" to 3.5" adapter, lol. That’s like 30 cents of parts and labour right there. You can even buy those made of steel for a few bucks because it’s so easy to make…

Try it out of the case if it starts up then. With ipmi working but nothing turning on when you hit the power button, it might be short circuit protection. There may be spacers that touch the board if the old X8 had different spacing for the screw holes.

Does it do anything? The x10sdv can be a pita to troubleshoot as there is nothing at all to diagnose without access to ipmi.

I’ve had multiple x10sdv, some had a corrupted bios, others were completely shorted, and they all had the exact same symptoms of powering on, but only spinning fans at Max and nothing else.

You can get a diagnostics card to read out the post codes, but it’s hard to find and often not cheap if you can find it at all. Should be the AOC-LPC80-20 iirc, if you want to look for it. If you get anything at all that’s not just 00, there’s hope a bios rewrite can fix it.

I’d probably not go with a T-Version, as those are capped to a specific TDP. So if you need more compute power, it’ll limit you fast earlier than a non-T CPU. Idle draw is basically the same, and usually the state of my hosts is idle or full throttle.

Also T-Variants tend to be more expensive.

Storage is a thing to consider as well. At best those machines offer a single NVMe and SATA, a lot even only one or the other.

Servethehome does have a nice series about those mini PCs, so best to take a look there which one to pick for your needs.