Hot answers tagged hand-luggage
I frequently fly all over Europe with shoe-box PC's or various measuring devices in carry on luggage. The measuring equipment is very expensive: € 250.000 is pretty normal for a single device. You don't want to let it out of your side or risk a baggage-handler to throw a suitcase around. And they don't like temperature fluctuations much (calibration issues). ...
I've brought computer parts resembling what you have onto the plan before without issue. They didn't even take a second look at it. You should have no problem, though the one part of the PC they might have concern with is the UPS.
I've carried a Transtec Senyo mini PC (http://www.pcpro.co.uk/transtec/transtec-senyo-610/29152/transtec-senyo-610-review) to and from Iceland many times. Usually with a laptop and an eee-pc in the same bag. I just make sure I take out each device and put them in trays just making sure that they aren't on top of each other (although I've never had issues ...
In general it is not forbidden (I suppose there could be exceptions, comment if you know any!), but you may get a bit of scrutiny. You will not be the first person that day to have large electronics on you; IT contractors bring all sorts of electronic hardware through security checks. I suggest taking it out of your bag and putting it in a separate tray, so ...
Only top voted, non community-wiki answers of a minimum length are eligible