Proximity sensor is above the Nokia logo. Use your right hand to touch the screen when on a call and all will be well.
Sent from my Lumia 900 using Board Express
Yes, thanks as this was happening to me all the time especially when going through a corporate calling menu...with speaker phone on...ie: the AT&T Corp store menu...was quite maddening..
A Mod @Nokia Discussion Forums also made note of this issue, stated to go into the Diagnostic app---> Nokia Diagnostics-Access Code: ##634#
Scroll down to the Proximity Test....as it should show a 'Yellow colored Circled'...then when you place your hand over the front camera sensor...it should then change to a 'Green colored circle'....
If the device does not perform like this, then the sensor is defective and the device should be returned for exchange...
My 3rd White L-900 past this test...however it is strange that the sensor (placed where it is)...would cause this issue....disappearing call menu...etc...
Thanks for this info....if I can find this thread @Nokia Discussion Forums will paste a link here...
Although this thread relates to Lumia 710 and Proximity issues (its more-then-likely) the same for Lumia 900:
Re: Lumia 710 Proximity sensor bug
[ New ] .
Hi olbez,
Thanks for your post!
Your can check if he sensor works correctly by going to diagnostic tools (if not available dial ##634#) and select the proximity test. You will see a yellow circle. When you put your hand over the sensor, which is in the left top corner of the Lumia 710, the circle will turn green until you remove your hand. If this does not happen as described goto a Nokia Care point to have your device checked.
Hope this helps,
Kosh
http://discussions.nokiausa.com/t5/...ia-710-Proximity-sensor-bug/m-p/1249769#M2792