do not use inexpensive power supplies, not worth the headache they cause, the time wasted finding they are the problem, nor the damage they might cause, and some are danger to life by not being isolated from the mains.
Definitely this! Bad power supplies are a nightmare. Maybe they work OK. Maybe they just die early. Worse cases are fire/shock, impossible-to-diagnose issues, dying
and taking your entire system with it, etc. Some of the cheap supplies are terrifyingly bad.
Years back I was working with Intel NUCs in an automotive application. They would have all sorts of strange behavior- crashes, reboots, stuttering, video artifacts, ...- when run off a cheap inverter. Apparently the inverter was sufficient to cause problems... after going through the 110Vac -> 19V DC adapter, and the internal 19Vdc -> 12/5/3.3/1.8Vdc converters.
Slightly more on topic, I've got a fanless Celeron PC like this one (looks like it at least, I don't have the exact model, but it's a J6412 chipset):
www.amazon.com/HUNSN-Fanless-Industrial-...g/dp/B0CGLR51SL?th=1
It's... fine. Jitter numbers are nothing special (~30000 ns IIRC), but I also haven't had any thermal issues with it. I admittedly haven't watched the CPU temperature directly to have hard data to back that up, and my shop space is stably at a relatively low temperature. I specifically wanted fanless so there was no place for dust, metal chips, etc. to ingress.
I suspect you can lock the CPU frequency at the lowest to keep temps down, though I haven't bothered.
