My buddy is in the same boat with his 70D so Ive been doing some digging trying to find him a solution. It would appear there is a "kind of sort of home remedy" but it requires the camera to at least turn on and be functional at some level. If you can get it to turn on again you can try setting it to record for a set period of time and take continuous snapshots. This may allow the chip that has broken its solder connections to reheat to the point the solder essentially reflows itself. The only other home remedy I can think of would be to pull the logic board completely out of the frame and apply significant heat directly to the affected chip. You'll need access to a hotair rework station in order to achieve the temps needed to reflow the solder but even this is not going to be a proper fix. Just like with the xbox 360's, this will be a temporary fix at best.

Put your ipod into DFU mode by holding the Power key and the Home button at the same time for aproximately 8 seconds. After a good 8 second count release the power key but keep the home button pressed. Hold the home key down for about another 10 seconds. This can be done whether it is or is not connected to itunes. Youll know you are in DFU mode when you connect it to itunes and it is recognized as being in a recovery mode, the ipod should also have no display at that time. At that point try doing a restore.

Level up your SNAPBACK skill by wearing trendy sun visors while thumb wrestling with your friends.

Both the wifi and cellular gps antenna are located at the top of the board, its possible there is corrosion damage on both of these components. Personally I would replace these components and see if it resolved the issue. A word of warning about the cellular GPS antenna, it is soldered to the logicboard so that is not something that is easy to replace without the right tools and know how.

I see this alot with phones that have been cleaned and bad parts replaced but wont fully boot. Sounds like the power management IC could have burned out or there is still corrosion somewhere under the shielding near it that you may have yet to clean. Another thing to try is to boot the phone with a different combination of the cables plugged in (e.g : everything plugged in except for the power ribbon). If its the pins on the battery connector itself your best option would be to install a new connector on the board provided the solder pads are still intact and you know the pins are not being inhibited by corrosion damage.

It looks like its going depend on how the phone went down, water damage, general wear and tear on components or maybe static shock from lightening? There is alot to eliminate before you start re flowing components. I looked into re flowing both the A5 and A6 processors a while back, all I remember finding were very short videos that didnt have much to offer in the way of techniques. Since then ive re-flown several different boards successfully, but they were not iphone processors, all I can say is that A6 looks like a doozy to get out of there without harming surrounding components.

Sounds like the ambient light sensor is not sitting correctly or is damaged. If the ambient light sensor isnt properly positioned it could be fooled into thinking that it is dark out and that there is no need for the screen brightness to be turned all the way up. Alot of the iphone 5 assembles will not come with the mounting hardware for the camera and ambient light/Prox sensor already attached. To be sure its not the light sensor you need to make sure these pieces are already installed on your screen. If they are not and you need to know what your looking for..... These mounting pieces are 2 small separate hazy/clear plastic pieces that line up the camera with the clear opening at the top and 2, less noticeable, opaque holes about 1/4th of an inch to the right and a few millimeters down. (hold the screen up to the light while looking at it from the back side and youll see them). They can be transferred over from the old screen by gently prying them free ( Be careful! they will pop off and fly several feet...

Assuming you purchased the digitizer with the IC already soldered onto it you could be looking at several different problems. Check these trouble spots first. First, check the digitizer IC socket on the motherboard, examine the pins inside the socket itself. If any of those pins look : dirty, not sitting even with the others, missing or damaged in any way this will render the touch input completely useless. A dirty pin can be cleaned using isopropyl alcohol and a q tip, anything other than a dirty pin will more than likely require that socket to be replaced by a professional. Second is to make sure you transferred the the tape on the home button ribbon from the old screen to the new screen. I havent seen this issue affect the touch input but it will occasionally mess with the lock and home button operations. Third, when sealing the new screen to the frame be very specific about how you feed the cable down into the frame, aftermarket digitizer ribbons are fickle when it comes to bends or creases. Some will...

ifixit iphone 3Gs Logic Board Replacment Taking out the logic board, or momentarily lifting it off the battery contacts, is the answer to shutting the phone down at this point.

Sounds like the classic case of a defective digitizer, but to be sure take a q-tip with 91% ( or greater) isopropyl alcohol and clean the contacts on the logic board and on the screen assembly. If you do not get any better results after cleaning then your screen is defective or maybe damaged. Best of luck getting the situation squared away.