Please Help! iPhone 4s - Black screen but phone is on and working

So here's what's happening. You have the 2 cables on your screen replacement, the longer more flimsy one is more than likely pinched. This will also cause your screen replacement to shift and not seat properly. What you'll need to do is get to the last step of the screen repair. At this point, the replacement screen is unscrewed from the bezel. At the top, close to the power button, seperate replacement screen from bezel being mindful of the cables. What you just did is freed the pinched cable. Now is time to reassemble. As your closing the gap between replacement screen and bezel, keep the longer flimsy cable taught as you seat the replacement screen to bezel. The replacement screen should fit like a glove! If it doesn't seat properly the first time, just readjust the long cable again. If it seats properly and you still have a black screen, remove replacement screen and inspect cables. This has happened in a few of my repairs. Just be patient and you'll get it.

Does the screen at least show the silver apple when you boot the phone?

This must be the problem with your display connector, as if it loosens then you might not get any display on your screen. The very first thing that you need to do is to get any other good and working LCD in order to verify where is the problem whether it is your LCD, Connector, display strip, connector etc. However there are a lot of things that you need to check. Here is a blog that has defined step by step solution in order to overcome this problem, i hope it will help you in resolving this problem.

http://blog.brokenlcds.com/iphone-4-disp...

I am a tech at Apple. You will most likely need a hardware replacement. If the reset and the restore did not help, it is most likely a hardware issue. I am sorry for your situation..

Had a similar problem. I would hard reset my Iphone 4s and it would turn on up to the apple logo but then would dim black completely. Knew it was running because I can hear the clicking from my lock screen. Tried everything but nothing was working. In desperation I simply asked siri, "Make it brighter" and low and behold, she made the screen brighter. I turned off "auto brightness" off right away. Five it a try If you can get Siri running..I had to get passed my lock screen though in order for me to access my Siri. Thank god I remembered the passcode without having to see the screen. Hope it works for you too

Apple Sucks, get a Droid! I've had a droid for 3 years, never had an issue at all. My wife and son have iphone's. They average an issue every 2 to 3 months. Apple just plain sucks!!!

i have a problem for i phone 4s phone working with sirri, but main screen is all black why ?