iPhone 5C force resetting when lightning cable is connected

Hey All,

I've got quite the strange acting phone here. I will list the strange behavior to start.

- Phone will power on and into the OS normally as long as it is not plugged into a charger but immediately powers off when a lightning cable is attached.

- On the rare occasion the phone does not immediately reset when plugged into power it will operate normally for maybe 5-10 seconds before resetting.

- Will get stuck in a boot loop occasionally, but this is not always the rule (seems to happen only when plugged into power during the boot cycle).

- (not 100% sure)The phone appears to charge while off, but it is hard to tell due to the fact that it will not stay in a powered down state 99% of the time.

Those are the main issues I am having trouble correcting. I have tried installing a new battery, dock and screen assembly with all necessary equipment. No effect.

I have tried all that new equipment with every combination of cable you can think of. Battery and screen connectors only-Dock and screen connectors without battery- dock and screen without battery, front facing camera flex and lock button flex...ect....

I have attempted to restore the phone but I keep receiving ERROR 14. This seems to loop back to the phone resetting itself when plugged into power, it will start the restore, itunes will get to "verifying iphone restore" and the phone will die and attempt to power on. This process happens like clockwork and I have not observed an exception during the 10+ restore attempts I have made.

A comment that was made to me about the circumstances surrounding this phones strange behavior was the fact that this phone has been used at least more that a little on a car charger (cigarette lighter style charger, not the newer style in dash USB chargers). Over the years Ive come to avoid using car chargers like the plague due to the bad reputation they have of destroying a phones charging circuit. My gut tells me that is exactly what has happened here. Is there nothing more that can be done outside of having it sent off to a specialist for repairs? Or am I missing something ?

Any Ideas help, Thanks in advance!