dso nano v2 question about insulation

the alluminium back case of dsonanov2 is connected to black gnd probe ?

no. it is a GND connected to the gnd of USB

which is also connected to the signal jack ground.

I wrote a question because i have last week a problem with my dsonanov2 bought some month ago.
I performed a measures with probe 10X, sinusoidal signal, washing machine alimentation, 230Vac.
All OK until the case of dsnanov2 touches the metallic case of machine connected to ground, that is also
connected to neutral of alimentation 230V.
Probably the gnd probe are connected to phase, other probe to neutral during measure.
Result: disaster
SD card damaged, some component near the card burned, the case of instrument presents sign of blase.

warranty lost ?? is adjustable ??

sorry for my bad english.


This has been discussed before: