Problem with phone app on iphone 3GS! When on a call it stays in sleep mode... why?

[mdee4]

Whenever I'm on a call on my iphone 3Gs, I pick up, put the phone to my ear, then it goes into sleep mode or whatever so you don't accidentally push buttons, then when I'm done with the call, I move phone away from ear but it just stays in sleep mode or whatever.
If I'm leaving a message to someone, then I must reboot (hold down home and power button)
or
if the other person hangs up on me then I have to wait forever for the screen to work, (I push home button over and over), then finally the screen turn on, and goes to homescreen!

How do I fix this?
Why does this happen?
Is this a software or hardware problem?
It's a jailbroken iphone 3GS

 

[calvy]

my girlfriend had this problem on her 2g. turned out the crappy rubber case she had on it were covering the proximity sensors.

 

[mdee4]

my girlfriend had this problem on her 2g. turned out the crappy rubber case she had on it were covering the proximity sensors.

Ohh ok. That could be my problem! But its the same case I used on my first iphone and it worked fine then.

 

[calvy]

Ohh ok. That could be my problem! But its the same case I used on my first iphone and it worked fine then.

My girlfriend used her pink griffin (i think) sport grip case for nearly a year before the problem developed. Basically, the rubber wore and was a lot more lose fitting on the phone. So when she held it up it was sliding down in the case. And the hole that was cut out to leave the sensors exposed was lower down than it should be, and the sensors were blocked. So we took the case off and all worked like normal. I'd say take the case off. If it works like normal, bingo. If not, we've narrowed it down

 

[mdee4]

My girlfriend used her pink griffin (i think) sport grip case for nearly a year before the problem developed. Basically, the rubber wore and was a lot more lose fitting on the phone. So when she held it up it was sliding down in the case. And the hole that was cut out to leave the sensors exposed was lower down than it should be, and the sensors were blocked. So we took the case off and all worked like normal. I'd say take the case off. If it works like normal, bingo. If not, we've narrowed it down

Ok, cool. Thanks. Ill check and see if that's the problem.

 

[SFStateStudent]

The case design was changed when the 3G was released. So, the same 3G cases can be used with the 3GS iPhone, but v1 iPhone cases cannot do the same.....

 

[calvy]

The case design was changed when the 3G was released. So, the same 3G cases can be used with the 3GS iPhone, but v1 iPhone cases cannot do the same.....

There we have it. I missed that detail. Get a new case!

 

[CocoaPuffs]

Maybe it's due to various modification you did with jailbreak.

 

[spencecb]

If it's the same case you were using with the original iPhone, it is undoubtedly blocking the proximity sensors on the 3GS. The sensors are in a slightly different position than they were on the original iPhone. You must use a case that is designed for the actual version of the iPhone you are using to ensure it fits properly and that the iPhone is able to function properly.