iPhone 3GS Sensors not working

[CheateR92]

Before time i opened it to remove the battery because it was in DFU loop because of iOS5. Now i realized that sensors are not working. When i make a call the screen should go off but it doesn't. Firstly i thought it is software, I updated to iOS 5 (from 4.3.3) but still not working. I googled what does the ribbon #3 is doing actually and i found that "Ribbon #3: Earspeaker and various sensors on the iPhone face". I thought to replace it but my speaker is working. Just the sensor isn't working. I think if it's broken they shouldn't work both.