water damage/missing smt capacitor/resistor from logic board
Hi folks!
So I dropped my iPhone 5s into some water on Friday night. Afterwards I disassembled it and left it in a sealed bag along with a load of desiccant bags and placed the bag in a vacuum oven at 40 degrees for a few days. I went to reassembly it yesterday and managed to break the FPC socket for the power button/volume flex cable.
I've a new socket ordered already and removed the old one today. When removing the old one though, I managed to wreck something else! I've lost a component from the logic board that sits right beside this FPC socket. I'll attach an image showing the component circled in red that I'm missing. Can anyone please point me in the direction of where to buy one of these?
Also, when working at this, I came across part of the board with "scorch" marks where I'm assuming the water has done the damage. I've cleaned it up with some IPA (Isopropyl, not ale! lol) and it looks clean enough now but I'm wondering what part of the logic board would this be for?
Can't see how to add a pic here, i'll post this for now and upload a pic and reply below with a link.
Cheers!
Chris
Update
The thing is, I've kinda gave up on it but I feel I have to know if the vacuum oven sorted the water damage!
I've attached two pics to this post. One shows the board after cleaning off the scorch marks and the other is just a screen grab off the internet where I've marked the missing component (red circle) and the green shows where the scorch marks were).
Update
Thanks for your help so far mate. Much appreciated!
So I've taken the motherboard right out and noticed a load more "scorching" on the underside of the area I'd marked in green above. I've an image attached below. Tried taking another through a microscope to show the extent of the damage through the little holes in the metal casing but it doesn't show up very well.
How would I go about removing this casing safely? Can it be done without damaging anything else?
I think I'd like to identify which components are burnt out under it and get them replaced. Maybe if I'm lucky this is all that was damaged before the phone powered down...
Update
OK, so I've the capacitor ordered and took the board out, removed the EMI shield with a heat gun to inspect the underside of the logic board. Thought there was a totally melted component but it was just some sort of black coating over a capacitor that had melted. I've before and after cleaning images attached to this post. Do you think I'd get away with not having to replace any of these components?
Also, what about that black coating? I've seen it on other parts of the board, would I need to recoat that cap? We've some black silicon in work, would applying a small amount from a syringe suffice?
Lots of questions, I know, so thanks again! I've a feeling this just might work!
Ist dies eine gute Frage?
1,1 Tsd. 
893 
2,3 Tsd. 
5 Kommentare
Those are EMI shields and are soldered ion. You can simply unsolder them to identify other burned components.
von oldturkey03
Good job removing the shields and cleaning it. You might get away without replacing any components. Now would be a good time to use a meter and see if the components are okay. You would need a capacitance meter for the caps. Or you could just go ahead and try it out.
von oldturkey03
OK, i'll give it a go! Will report back if I get anywhere. Cheers!
von operationbrokenspoon
Hi Jessa,
Thanks for the additional info (and the kind comments lol)! Could you show/tell me the location of the diode you’re talking about? I’ve bought a dead iphone 5s to salvage parts off so I’ll be able to swap it out along with anything else I might come across that needs changed.
I’ve had a lot of trouble soldering the FPC connector back on. I just don’t have the equipment for it here (just have an ordinary soldering iron and a microscope!) but I’ve been wondering would I be able to use some silver loaded epoxy to ‘solder’ it on?
We use it for attaching surface mount resistors, transistors etc onto the products we build at work but it requires being set on a curing station (hot plate) for 45 sec - 1 min to cure the epoxy. I don’t think I’d be comfortable leaving the entire logic board there for a minute in case it damages anything. I was thinking as an alternative, I could place the FPC connector on the board (with the epoxy of course) and cure it with a heat gun. I think this might be ok if I shield the other components from the heat gun so nothing gets blown off the board. Plus it only needs to be at 175⁰C for a minute so I don’t think that’ll be enough to melt the solder on the other components…or at least I hope so anyway! I suppose there’s always the chance of this melting the FPC connector too but I could try it out on the donor board first as a test before I do anything with mine.
Have any of you guys any opinions on this? Cheers!
von operationbrokenspoon
operationbrokenspoon, there really isn't a good substitute for soldering. Consider sending it to someone who specializes in microsoldering to repair the connector for you.
von oldturkey03