Dropped my phone now blue vertical lines

Try pressing the home and power button at the same time but holding it down until it shows the apple sign.

Sounds like damage to the digitizer or graphics module...take it to an Apple store genius bar - out-of-warranty replacement for an iPhone 4s is $199 in the US.

i was using my phone and my screen went blue with lines in it, perfect condition. iphone 4s 32g and just bought about 2 months ago.................... Im not impressed................

Try backing up and restoring your device in iTunes and if that doesn't work contact apple support as I imagine that so long as your phone hasn't suffered any physical or liquid damage they'll be happy to replace it.

The same thing happend to me. I tried restoring but it did not help. I have not gone to the apple store yet. Is there any other way to fix it ??

This may help, https://discussions.apple.com/thread/4474708?start=0&tstart=0

This has happened to me too!!! should i go to Apple store??????

First try a reboot by holding both the power and home buttons until the apple logo appears, ignore the red slider if that appears. If that helps, great.

But it probably will not and you should then go to the Apple store genius bar. Be sure and make a backup first, in iCloud is best, so that you do not lose content if the decision is to replace the unit. If you have an iCloud backup, that can be restored by the techs while you wait.

Worked perfectly! Thank you

do not restore iphone 4s, just follow these steps, go to settings - general- accessibility- switch control, if switch control enable just make it disable, blue line will go,

thank you

In iphone 5 I had a problem with horizontal and vertical lines, so used this steps, and its gone. Thank you @jitthendran

Thanks a ton. Solved my problem. Cheers

How do yoy disable switch control