Reassembling iPhone 3GS to retrieve data

Hey guys and girls,

I've got my mother's 3GS laying in pieces on my desk, as I attempt to put it back together. We took it to a guy in town to replace the battery, but according to the message he left us on our phone, he's never done a battery replacement on a 3GS.

Instead of looking up one of a dozen guides, he's taken the bloody thing completely apart, and possible damaged the motherboard near the Connector #7.

My mother upgraded to a new phone, and we just need to get the data off it now. All the ribbons have been removed, unplugged, and even unscrewed from the metal ring, it's a nightmare.

I want to put it back together, bare minimum to get it to turn on, so that we can get the data off of it. Do I need to reattach all the ribbons, or am I able to just connect the core ribbons (1, 2, 3, 4)? We do not need it to function as a phone, we just need it to turn on.