Chosen Solution
so definitely dock connector issue. as for the boot loop, i would try putting in DFI mode which is a deep recovery mode for iphones then itunes would recognize it as being in recovery mode and you could try restoring it. but i would also replace the battery to ensure its not a matter of power source outage. so try replacing the battery and dock connector first.
Have you tried testing the phone by replacing old screen? You don’t need to completely dismantle, just pop off LCD and digitizer connectors and plug old ones back in. If phone works (minus touch capability obvs) then it sounds like a problem with screen. Dont always buy cheapest screen you can find, look at feedback ratings for seller. Also check everything is grounded properly all the gold connectors are where they should be etc. If you can get it in DFI mode then mac will have easier time finding it.
Change your battery and check the battery connection. Check the voltage on the outside battery connector with the phone plugged in and the battery removed. Your computer will not have enough amperage to power up your phone, if the battery is completely discharged. Anything below 2.8V will put the battery in a no-charge state. You could try to “quickstart” it, by briefly connecting a 9 volt battery to the iPhone battery. Just for a few second, which should be enough to get the iPhone battery above that threshold. Watch the polarity of the battery and connect only like contacts, do not reverse the polarity.
Thanks to you both for your help! @ gtcoodyscoops: I don’t think that the dock connection is the problem since when I plug the iPhone to a power source (other than the computer) then it turns on. The problem seems to be related to the power source. I can’t put it in DFI because for the iPhone to enter in DFI it needs to be plugged to the computer however mine when plugged to my Mac doesn’t respond. @Steven: I’ve already tried to plug the old screen into the phone but no luck. I also think that the grounded pieces could be the source of the problem or the battery… but I can’t seem to identify precisely the problem. Last I don’t really feel like spending more money on this device (battery)… Many thanks for your advices! Martin
