I just got the alcatel onetouch idol x+ abuut two days ago and for some reason now it wont let me change the screen brightness..... or even 'select' it for that matter! It wont let me do it on both the drop down option or when i go into actual settings.....any help?!?!?!??
Even if the phone doesn't have a removable back, you just hold the power button down for 5-10 seconds and once the phone does a hard reset (turns off completely) turn it back on and try the feature again.
As Ahmad said if these options don't work you can take it back to the store you purchased it from within the first 14 days. Hope this helps.