I have Karbonn A9, Android 2.3.6.

When making calls the screen turns off and comes on pressing the power button. But sometimes it fails to come on, forcing me to restart it by removing the battery. Any clues?

  • 2
    Try to disable the proximity sensor, I had similar problem with my Galaxy Ace and it helped.
    – Renan
    Commented May 26, 2012 at 17:00
  • I don't think there is an option under settings to turn off proximity sensor. (In karbonn A9) Commented May 30, 2012 at 4:35
  • Does the screen not come on when you take the phone away from your face?
    – cjk
    Commented May 31, 2012 at 6:39

8 Answers 8


I purchased an A9 today and I'm having the same problem. If you have a screen guard, make sure it is not covering the proximity sensor. That worked for me.


I tried Screebl, Screen on and Smartlite but none of them seemed to fix it. Finally tried *#36#. It opened up a screen with a list of items one of which was Proximity Sensor test. I selected it and saw text written in Chinese/Korean language. I tried my luck clicking a button (which showed some Chinese text). It did something and after sometime the button disappeared. I am not getting screen off during call/after call issue anymore.

  • The *#36# solution worked perfectly for me on my Karbonn A9.
    – user17415
    Commented Jul 26, 2012 at 12:38

I faced a similar problem, resolved the problem. It was to do with Proximity sensor and the screen protector blocking the proximity sensor. You should check for the same and cut off the plastic from the blocking area. Note that the proximity sensor is at a small circle at the top left of the phone. let me know if it worked

  • Does the phone comes with a screen protector on it? I had the same problem and sent the phone for replacement. Commented May 30, 2012 at 5:25
  • @sElanthiraiyan: In general, the screen protectors that come on phones when they are new have cutouts where the proximity sensor and front facing cameras go. However, I have noticed that some screen protectors that you can buy do not have these cutouts, although some do.
    – MrWhite
    Commented Mar 16, 2013 at 16:39

Before cutting the plastic off of the proximity sensor, try cleaning the area out with a damp Q-tip. I had this problem and it was caused by a bit of dust/whatever accumulation.


I had the same problem, and dialing *#36# to reset the proximity sensor fixed it.

  • Tried the *#36# proposed solution by dialing that sequence as per a normal call and received the following response "USSD code running..." followed by: "Connection problem or invaild MMI code." Any other suggestions?
    – TonyMo
    Commented Oct 1, 2012 at 16:41
  • @TonyMo dial it with the stock dialer, it will automatically open the options for you, you don't have to press the dial button. If you are trying the code through third party dialer then its won't work. Hope this will help you.
    – avirk
    Commented Nov 15, 2012 at 16:52

Try using Screebl. It fixed the issue for me.


If you are rooted, you could ramp up the minimum CPU voltage when the screen is off. That will certainly fix your problem--

OR if you have a lot of applications running in the background all the time, you could set your min free mem values a bit higher.

But if you aren't rooted-- Keeping the screen on is not a desirable solution since it will drain your battery very, very quickly.

Since you're on 2.3.6, I would say a bit of patience could do the trick-- Your phone should only freeze once in a blue moon--

Try uninstalling some applications that are high-ranked on your battery usage.


I have Karbonn A9, Android 2.3.6.

When making calls the screen turns off and comes on pressing the power button. But sometimes it fails to come on, forcing me to restart it by removing the battery.

Problem Come Sence i Leminat mobile .. before it was Work Fine..

I got Solution here :

Screebl Lite app install and active it.. proximity sensor Off app install and 'disable accidental lock' Disable IT

it's work on my Karbonn A9 mobile

tommorow i will remove lamination of mobile then ??

should Problem will not come again..

  • Screebl was already mentioned as a solution in this answer
    – ale
    Commented Jul 26, 2012 at 14:07

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