Screen black, logic board overheating. back-light filter issue?

Hi there,

First time posting but long time browser of your Forum and site. Great work.

I have an Iphone 5 recently purchased. It does not turn on even when I use other screens that have been proven to work on another Iphone 5. It does not have any water damage. I have tried to use other batteries but still no luck. It also appears not to be charging properly and I have used a new charging dock as well.

When I plug the phone in with my charge cable. after maybe 20 or 30 minutes Itunes SOMETIMES picks it up but an hour will pass later and the battery will still show 0% on Itunes. However, EVERY single time the board will get REAALLYYY really hot. way hotter than it ever should and the heat seems to come from under the plate where the screen connectors are on the front of the board. I have read that heat could come from a short but I am unsure if I have one.

I recently took that sticker covering the backlight filters off and had a look under my microscope but I am unsure if there is an issue. I saw a black section and when I looked at the schematics it showed it as "DZ4" and I am unsure what that is or does (even after a google search). I have also got a photo of "C298" (i think) and it looks black but im not sure if that is because it is burnt out of because there is some glue residue on it. What does DZ4 and the one in the photo (which may/may not be C298) do? Is the DZ4 burnt out? or is it meant to look like that? (i have seen google images of other boards and it also looks black). Is the second capacitor burnt out?

Why does the board get so hot and get recognised in Itunes (sometimes) but still not have the screen turn on? and is there a reason why it gets so hot?

Any help will be greatly appreciated. I don't do soldering work as I do not have the tools but any help will be greatly appreciated.

sorry for all the questions....

EDIT: Upon Further Inspection and watching one of Jenna's Youtube video's about an iphone 5 that doesnt increase the battery percentage, I had another look around the batter connector point and then at the connector for the dock/charge port. The battery capacitors were all there and fine.

However, as seen in the photos, It appears that two capacitors are missing... probably from when the previous owner was trying to pry open the dock flex cable.... Is it just me? or are there really 2 capacitors missing? and does this affect any of the problems I mentioned earlier? Does anyone know what they are?

Thank you Kindly in advance!

Turns out the missing pieces in the last two photos are DZ13 and DZ14 and that they connect somehow to C99 and C102. However I am yet to work out what these all are and what purpose/function they hold.

Is there a website that can explain this to me? I have never read a schematic before and so I am still struggling to work it all out but I will give it another go.

Thanks in advance.

Aleks