iPhone 4S Water Damage/Teardown Help Requested

Hi Andrew,

Thanks for your reply. I was able to follow your guide to get the logic board out. I then proceeded to remove the EMI shileds. There was some corrosion on the leads to the A5 chip. I'm getting errors related to the Toshiba flash chip and am wondering if there is some corrosion there. However, the shield over this chip appears to be secured much better than the rest. I'm wondering how you removed this in your teardown.

Thanks,

Jason

I'd have to see a picture of the shield to be sure I'm giving you the right advice, but in general the tighter shields are often soldered on, and the only way to cleanly remove them is by desoldering.

You'll need a clean, fine-tip soldering iron, a small sharp tool like a sturdy pick (I use one of the automotive picks), and a small vice (or three hands).

Heat up the iron and put a bit of solder on the tip to improve its heat conductivity. Run the tip along the solder pads on one side of the shield, being careful not to touch any components surrounding the shield. While heating the solder pads, wedge the pick into a corner or hole in the shield (being careful not to go too far and damage the chip inside) and gently pull straight up. You need to apply just enough force the shield will come up without deforming it. Be careful with this part.

Once the first side pops up, work your way around the remaining sides, melting and pulling with your pick.

Thanks again Andrew. I'm assuming this is one of the tighter shields, but I've added a picture of it to my original post. I think this one might be out of my league as far as such fine desoldering goes. Would an ultasonic bath in alcohol be out of the question to get at any corrosion that might be under there?

some people use a scalpel to cut the shield along the upper edge rather than desolder.

That is the sort of shield we'll desolder for a teardown, but if you're not confident in your abilities, an ultrasonic alcohol bath might not be a bad idea. If you're not too worried about destroying the shield, it is possible to clip the legs with fine-point wire cutters—just be very careful not to cut any deeper than the legs, or you might damage the chips inside.