Edit: a 35*35 mm² heatsink (with less than 35 mm height, I assume?) will be far from 1 K/W -- more like 10 K/W. You would need a much more hefty heatsink to passively cool the DHO.
On closer examination; While that SBC itself is fanless, their temp spec says "
@0.7m/s Air Flow"., BTW it looks
significantly shorter than 35mm height. They also don't have a FPGA running balls out, contributing to the heat load.
Incidentally, this is a very warm product, naturally. Uncomfortably so, IMHO. When I unplug a USB connector it's HOT., BNC's are as well. I forgot to measure the temperature on the connectors during my fan testing, but the last mod I did cooled the I/O's considerably.
BTW: @shapirus
I watched that video you mentioned, and have some issues with his methodology. I'm not saying it was flawed per se', but I just can't put much confidence in some of his findings in general. Ex: when Rigol did their HALT testing, I doubt they turned it up on end, dumping heat into the power supply section.
-From what I've observed, these scopes don't really need much of an excuse to reboot. Sometimes, I'll look over at my DHO because it's clicking and flashing in the middle of a reboot cycle. For no reason!
(Before anyone asks: ^that's before I opened it)