the parts for connections for 8gb and 16gb, as long as they are both 3g, are compatible.

if you are finding that the phone won't power up after a logic board switch you'll need to check

1. recognised by itunes

2.vibrate toggle on/off works

if these work then it is either a display issue in which case you need to check connector 1

3. if nothing happens then you'll need to check connector from headphone jack, connector 4 (the dock) are on properly and the battery connections/pins aren't flattened etc.

get back to us if this doesn't work.

I'm assuming that you bought the 16gb as a working logicboard, if this is the case then you can always try getting a refund.

Hi,

thanks for your replay.

no iTunes reaction, no windows. all cable checked. I thought, the board isn't compatible, but now i am sure, the board is damaged.

I will contact the reseller.

Thanks again for your help

cu Etienne