How can you effectively identify a component that is causing a short?
I currently own an iPhone 6S , which has a CLEAN logic board (no water damage and no visual physical damage) , and the iPhone does not power on at all. It might be a short in VCC_MAIN, but I have no idea how to identify the shorted component. How can I truly identify the shorted "line" and the shorted component on the logic board that prevents my iPhone from powering on? Any suggestions would be really appreciated. Thank you all for viewing my question! (PS; Basically, I am a novice at mobile phone repairing, and I would like to investigate and solve the problem by myself so that I would gain a bit of experience all in all)
UPDATE: I now know that VCC_MAIN is shorted, and I now seriously need to find an effective and time efficient way to identify the cause of the short. Correct me if I am wrong. Now, I am powering on my DC power supply and adjusting the voltage to almost 4 volts. I then attach a wire to an anode side of a capacitor (which is the rail side of the cap) and attach the probes of the DC power supply to that wire. I then use a freeze spray to spray the whole logic board in order to find an area that heats up. It is usually a cap that is shorted, so I would check if there is any cap that is heating up. If no capacitor heats up, then this would mean that I have an issue with a circuit that gets VCC_MAIN passing through. I should then check which component causes that short, and then try to remove that component of that circuit (which is usually the one that is being fed by VCC_MAIN). That's all what I have learned from my research. Am I doing anything wrong at this point? I need the advice of all of you people in this forum! Please help me here! Thanks a lot in advance.
Is this a good question?