[Xperia Z3 General] flatpedals:
This is a little 'project' I had going on that I want to share.

A friend of mine brought me his dead Z3 (D6603) telling me it didn't start anymore after an OTA. Worth mentioning he doesn't know **** about any tech related topics.

It didn't start whatever I did. I've been wiping and flashing stock .ftf files with flashtool for two days when I started thinking about a possible HW problem, ditching his stupid OTA fail theory which I think is just a big coincidence.

He was trying so hard to convince me that the OTA fail is the problem... he said that battery was only at 60%, not fully charged as advised by the OTA installer and that was for sure the problem.

Searched for a disassembly tutorial and started unpacking.

Took off the back cover with a suction cup and plastic pry tool. I refused to use a heat gun because I don't like soft adhesive sticking all over my hands and tools.

The cold adhesive just popped out along with the battery, whose adhesive pullers I didn't notice, but I didn't ruin it's connector, fortunately, but it came off too easily if I think about it now.

After a bit of searching, I could see water damage proof on the main board, around the big flex cable slot.

Some photos here: http://imgur.com/a/3q6nF. Sorry for the bad quality, I grabbed them quickly, I didn't think I would ever use them.

I was a bit amazed to see water damage in a water resistant phone, not waterproof though.

Knowing my dickhead friend, I knew something was odd here. When I explained it to him and showed him the proof, he suddenly mentions to me testing his 'waterproof' phone the day he got it, in the shower, like a month ago.

Ok, cool, buddy, you didn't think about telling me this earlier, ha? :)

Dismantled everything, even the metal plates that cover the chips, cleaned with a tooth brush and alcohol, blown with compressed air, let to dry and assembled.

Boom, the phone started. I could hear the sound from the boot animation, could use the touch, feel it vibrating as a response but no alive display, so I used a flashlight to see the working display, but it was lacking brightness, 0 percent.

Then I took a good look at the large flex cable and the port on the board, with a magnifying glass.

Three pins on the slot were burnt, basically absent, and some others were black and burnt, but in place.

I immediately thought the main board is toast. Nobody could solder that small pins for us in town.

We ended up buying a second hand Z3 with broken display&touch assembly for a little over 100 euros.

Swapped the motherboard and bam, my friend's Z3 worked like a charm.

It was a bit of a risk buying that donor if I look back at it, because of the broken screen assembly that could have been our problem here, but those burnt pins made the problem pretty clear for me.

Amazingly, the flex cable, with the same amount of pins, was fine.

About that back cover adhesive that I've mentioned earlier, I think it came off much easier on my friend's Z3 than on the donor.

The donor was a tough mothafaka to crack, I eventually heated it up and used some paper cards to prevent it from sticking back. So I think there was the factory problem of the phone.

Now I'm stuck with a Z3 missing the main board and display&touch, a really dumb friend and his fully functional Z3. Well, apart from not being water resistant anymore (since I replaced the double adhesive tape on the back cover and I'm not trusting it).

Oh, it was never water resistant, thank you, Sony.

I hope you enjoyed my fairy tale or that it may be useful to somebody. cheers.