Chosen Solution

Hey, I recently replaced screen to my old iPhone 4. After reassembling I tried to boot it, but it just tries to boot all over again. Disassembled the device and checked all the connections, still not working. I replaced battery, home button and power button flex cable also, so they should work properly. I tried with the old battery too, (I removed it as a working part) but it’s not charging it. (the old battery was empty and it worked before I started the screen replacement procedure.) Looks like the charging connector is broken(?) Also, my computer(PC) don’t recognize the phone and neither the iTunes. A little black component just below the righthand screw(which holds the protective shield for charging dock flex cable) have been cracked, can that cause this kind of problem? Thanks for help! Update (01/03/2018) Thanks for help Minho, I uploaded a picture about the component. I don’t really understand the picture of the logic board’s components, so I’m not sure which one of these it is.

I guess that depends what “little black component” is damaged.

A picture here would help but if its Q2, most certainly that is the issue. If it’s U5, then possibly but realistically, if you have damaged components that you can see with the naked eye, there is possibly more damage as well that would be seen under magnification.