water damage, now working, but dim display, need help with cleaning

This guide should show you how to disconnect all the cables that you need to. I agree with Nat though on the diagnosis.

My standard cleaning advice:

Once you're at a step where you can see the logic board, you should use some strong isopropyl alcohol (90%+) and a soft brush to remove any white-ish residue you see. Let the device dry <thoroughly> to make sure all liquid is gone (this will likely take a day or two in a warm, dry place if the device is opened up. Putting the iPhone in a bag of rice can also be useful at this point.) When it is dry, put it back together, and you will have your best chance of it working.

I dropped my 3G iPhone into water too and experienced similar problems, dim display at first and then after a few minutes of water damage nothing. I had given it up for dead at first until I discovered this site...

I followed the instructions to remove the display up-to step 6 and found drops of water 'here and there' within. Unfortunately when I pulled the iPhone apart at step 3/4 connector 1 pulled out by itself (Ooops!) so be careful.

To remove the connectors I used a small size 0 jewellers screwdriver and a very light/careful touch when prizing them up VERY gently from a corner, they will pop out but you will have to be very careful not to damage the cables (I did not have a plastic 'spludger').The connector marked 3 with the tab can be flipped up using the screwdriver too.

This is as far as I went on mine as far as disassembly was concerned.

I mopped up all the drops of water could see and gave all the exposed electronics a good dry with a soft tissue. I then put it all back together left it in a dry warm airing cupboard for a few days and then fully charged it up. I guess I was lucky...it has all come back to life !