Non-working 3GS's: hardware related bootcycle?

[oldenburg]

Hi!

I recently bought 2 iPhone 3GS's really cheap, they are both damaged.
(Just want to make it clear that I love repairing electronics, when I bought this I knew it was a gamble.)

One has got a cracked screen and minor water damage. The connector to ribbon no. 3 is broken (that plastic cover thing is missning). When I boot the phone up it gets no backlight, otherwise it works just fine. If I try and push the ribbon cable further in to the connector I get backlight, however this forces the iPhone into an endless Apple logo bootcycle(which I have tried to fix using various methods, seems to be a hardware error though)

The other iPhone appears to be intact, however it does not work without being plugged into the wall. I've switched the batteries from the other iPhone to this one which resulted in that it started to do reboot loops after I got to the Emergency Call - menu. The iPhone stops working instantly if I unplug it from the wall socket.

Has anyone experienced something slightly related to this? Any tips on some module to switch from one iPhone to another?

I'm very thankful for any sort of response on this, thanks!

 

[Amylittlehands]

The other iPhone appears to be intact, however it does not work without being plugged into the wall. I've switched the batteries from the other iPhone to this one which resulted in that it started to do reboot loops after I got to the Emergency Call - menu. The iPhone stops working instantly if I unplug it from the wall socket.

my dad recently replaced the back and front screen of my iPhone and I get the same as you, only I'm not lucky enough to even get the Emergency call menu. My phone only powers up when plugged into the wall charger, after 10 seconds of the Apple Logo it switches off, I'm baffled and might look into replacing the battery and the dock connector.

 

[oldenburg]

Yeah, mine does the exact same thing now since i switched batteries. Im going to try and switch the connector dock from the "backlight-less" iPhone to the other one.
Let me know if you get yours to work again, good luck!