Bose Life style 28 shuts down

[kw1997]

I have a life style 28 system which was bought in US and runs on 110 V.
Since i moved to Europe , I started using a step down transformer with a surge protector but the system shuts down after a few minutes of use. Can somebody tell me what is the problem. May be because the transformer is not an isolated kind?. Would be grateful for your views.

thanks