Hi askewpiste,
I reapplied the thermal paste, removed the m2s, removed the bottom and side covers, removed the ethernet cable and rerun the test with a desktop fan blowing on top of it. But even if that works it would be an unacceptable solution, an almost naked device that gets overheated in 16c/60f room temperature would be completely useless.
A previous post suggested trying out a custom BIOS, however it is not for my exact device and could brick it I guess. The best I can find in CWWKs support site is 先锋版N100-N200-i3-N305-BIOS.iso which I *assume* covers my device, it is however older than my current version.
I've contacted CWWK but do not really expect any kind of help from them (I knew that before buying the device).
This is getting really annoying, I'm down ~600 euros so far (device, ram, couple cheap m2, heatsinks, thermal paste x2, new power supply) and even more on other equipment I was supposed to attach to it (mainly a couple of 2.5/10gbps switches and a custom nas).
I found a 32GB version of the RAM you mentioned earlier but that is another 130 euros, I'd buy it if I was sure it would work ... but the device 'feels' extremely unstable and I am unable to accurately pinpoint the source of the problem ... sometimes it takes an hour for memtest to return an error, other times I get 10+ errors in the first 10 minutes (all that without changing anything AT ALL, not even moving the device an inch, room temperature is pretty stable during the day).
I should just admit that I made a mistake purchasing this and move on but damnit its easy to get obsessed trying to figure this out