Screen doesn't blackout when on phone

[sap007]

On the iphone 4 whilst I'm on the phone making a phone call the screen doesn't black out and my face ends up pressing buttons most commonly the mute or hold button.. does anyone have any idea on how to lock the screen so that this doesn't continue to happen to me?

look forward to your responses.
Simon

 

[Big-TDI-Guy]

Use your warranty - get it swapped / checked at the store.

Use speakerphone.

Or - there are now apps you can download... however, I'd say fix the problem on Apples dime - not yours.

 

[JBDC]

My phone has the same problem...

It's the proximity sensor. I just bought an iPhone4 today and previously had a iPhone3Gs...which didn't have this problem..I talked to my friends who also have 4's now...and they experience the same thing..Apple supposedly issued a fix for their proximity sensor back on the 4.1 software update. But I deftly notice some tweeking still needs to be done..I have put 2 ppl on mute while on the phone by my cheek hitting the phone and my friends have too or accidentally hung up on people. I guess we have to wait for apple to send out another fix.

 

[iRepair]

This is a fairly common problem for iPhone 4 users that supposedly was addressed with the last software update but the fix doesn't seem to have worked. As mentioned in the previous post it is the proximity sensor that is not activating. Your best bet is to take the phone back to Apple for replacement although with so many users having the same issue they might tell you to wait for another firmware update.