Unknown iPhone 4 soldering

Hi friends!
Yesterday I took an used iPhone 4 from an auction that I win. This worked great all the night.

Today I opened it to change the broken glass when I find a strange situation. I saw a wire soldered from the middle of the logic board to the upper part (photo1, left iphone). I naively disconnected these strange cable because I thinked that were leavings of Led Apple Mod, but I was wrong. I tried to power on the phone and the FlashLed switched on, then switched off, and now if I try to power on the phone the screen goes black, then shut off, in loop. I saw that the first point of that strange solder was in the C67_PMU but I didn’t noticed where the second point was. Maybe in the LP18_RF chip(that is missing)? I saw only that the wire go on the upper part of the board. I don’t really know what to do to resurrect this iPhone.




Thanks in advance for help