You will need
  • service manual to your mobile phone.
Download service manual for your model of mobile device, it will typically provide for special codes to exit the engineering menu. Please note that it should not be confused with the usual user manual, it does not contain even a usual service codes. Such manuals are usually quite easy to find in the public domain, also they are often written in a language that does not facilitate the task with the output from the engineering menu.
Exit the service menu of the mobile phone using the red button reset call. Also can come and button on/off the mobile device. Try to press and hold it for a certain time, it is possible that the service menu is closed this way.
Search the Internet combination to exit the engineering menu, the appropriate model of your mobile device. Typically, such information can be found on websites and forums dedicated to mobile phones with certain manufacturers.
Reboot your mobile device to exit the service menu. For this you need to have a special connecting cable, software in accordance with the version of the installed flash card and so on depending on which way the firmware specific to your mobile device – in some cases, the update comes with memory card and others with computer when connecting the device.
If you have not helped any one of the items, contact the special service centers for repair mobile phones, it is possible that they will help you fix the problem with exiting the service menu. Next time, try not to use these codes unless it is absolutely necessary, because it is not always a good thing for the phone.