I know how easy it is to change a power supply but maybe he didnt... and he lives in bum-**** country bumpkin france, who knows how easy a power supply is to attain there. I am not saying it is all 100% on the straight and narrow but who knows really... bah.
France is on the same level as the US in terms of technology... Computer stores are everywhere.
In any case, I'm guessing he reused the wire from the power supply to the wall outlet from his old computer if he didn't use an adapter, otherwise he would probably have thought about the voltage difference...
I've moved back and forth between France and the US 3 times, and every time, without fail, something would blow up... It's just the kind of stuff that completely slips the mind for some reason...
There's something I thought about:
If something bad happened to him, his bank accounts were most likely closed. Hence, payment for his internet bill could not be made to his ISP. Hence, the ISP probably knows that something happened, because when someone is deceased, they have to contact the person's family members to collect their dues. (Or, ultimately, his family closed the account and the ISP is aware of the circumstances regardless)
I'm not sure what the laws are in France regarding the release of clients' personal information -- it's probably impossible to get information without a letter of attorney of some kind, but who knows, it might be worth a shot...
So if anyone wants me to, I could write to the ISP, in French, explain the situation, and see what would be required in order to obtain this kind of information.
Getting a letter of attorney is not a hard thing to do -- I'm sure at least one person here has a workplace legal department that can provide legal services to employees...
Of course, I'm not directly involved with the situation, so pardon me for intruding ; but if the main reason you have not been able to find out much is for language reasons, feel free to contact me, I'd be happy to help out.