Galaxy S2 i9100 not working, what to do?

Hi there, we are having problems with my wife's S2 i1900. We can't turn it on. We've tried some reset procedures but nothing seems to work. We have two batteries both with app. 4.1 V charge (0.7 mA), which should do something. The continuity at the + and - poles at the phone (no's 2 and 4) is 0.03 Ohm.
We've tried different chargers, resets, but nothing happens. Is there something else we can try or do, to see if there is any life left in this phone? Would be nice to fix it and use again.
Thanks, cheers
Henkjan

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