Your favorite Apple, iPhone, iPad, iOS, Jailbreak, and Cydia site.
Thread: Signal Problem
03-16-2011, 07:29 AM #1Signal Problem
I have a 32gig Iphone 3GS. It is at 4.1. It is not jailbroken. The issue I am having is when I insert my AT&T sim everything is fine until I enable 3G and then the signal goes down to No Service. I checked both the antenna cables on the motherboard. Not sure which is the one for the cell signal though and both seem plugged in well. Does antone know what might cause this? Or what I maybe should replace to fix it?
03-16-2011, 12:02 PM #2
the bottom antenna plug is for the cellular signal i believe.
Check both of those plug and socket on the board.
it is not the same as on the 3G
03-16-2011, 04:57 PM #3
Couple things to check for. The previous poster was correct in saying that the signal antenna is based on the dock connector (Bottom with the speakers). There are two connections (cellular and wifi) that are located on the top right of the dock connector and the bottom right of the motherboard respectively. However, this wouldn't pose a problem with you turning on 3G and the phone going to no service. You could, however check the following things and see if it's an issue.
1) On the right hand side of both the motherboard and the dock connector, there is a small gold spring-like pin that grounds to the silver bezel. Make sure that both of these are number one, intact, and number two, are contacting this metal bezel surrounding the phone.
2) Make sure again that the antenna cable (circular-looking connection) is firmly connected to the motherboard. It should provide a satisfying "snap" once it's connected to the motherboard. Also make sure that at the top right of the motherboard that the wifi flex cable is both connected to the motherboard using the same method, also make sure it's grounded to the vibrate switch housing.
If all of these are done correctly, there is a possibility that your 3G radio is not working properly. If you're lucky, a software restore will fix this. If not, you will have to get a replacement motherboard, as the 3G radio is near impossible to replace. Also, if your phone is under warranty, just take it to an apple store and have them look at it.
03-17-2011, 07:35 AM #4Thanks guys
Everything seems connected and the pins on the right are indeed touching the bezel and still the same result. I ordered me a new dock connector that will have a new antenna. It cost less than $8. If that doesnt fix it, I guess its the board. Thanks for your help.