Dropped in water - now locks and goes to sleep automatically
A friend's iphone had water damage. It was cleaned by a professional but there are still issues.
Screen works ok, iTunes recognized it and restores it, all is almost ok, BUT on 4.1 there was this "Temperature" warning all the time.
It was updated to 5.0 but now when I am trying to set it up, out of the blue, the lock screen appears and when I slide to unlock the dial pad appears and I can only dial an emergency call. After some "slide to unlock" efforts the set up continues only to stop some seconds later when the lock screen appears again automatically.
When connected to iTunes it goes into sleep mode a few seconds later and iTunes stops "seeing" the device.
Which IC do you believe is fried?
I decided to look further into the soldered shields. As it seems the "professional" cleaning by a repair company hadn't been so professional. Two resistors were broken off their positions. I feel that this is causing the issue. Is it possible that an ultrasonic bath not suitable for electronics (i.e. without sweep option) could cause a small resistor to pop off?
um... the temperature thing is I think controlled by the battery (it is on other generations) Have you actually replaced the battery permanently? you don't mention it above, but you can have stupid problems like you mention if it is "shot".. I would start there, restore, and then see what happens. Need to find the schematics.. the functions you mention are likely on power ic and yes you do get partly failed ic if say one pin/connection whatever is corroded/shorte
Personally I do not think that this is caused by a bad IC, they either work or are ruined. It is possible that you have a bad solder connections etc. You might have to take another look at the professionally cleaned logic board. If someone cleaned it professional, why would they leave it with errors like you have. I would follow this guide http://www.ifixit.com/Wiki/Electronics_W..., replace the battery and reevaluate from there.
You can also check the schematic and check the test points. Download it from here