This happend to me once and I realised that my modem was turned off, so I turned it on a it worked. So maby just try it.
Black screen.
If you get a black screen after installing mods, then it is a compatibility or incorrect install problem. If you get a black screen normally, force an update and this will probably fix it.
Maybe you don't have Java.
You sit there disappointed...
This means that Minecraft has crashed. Please try and load it again.
if you mean a black screen then it means the too many items you downloaded dose not support the version of minecraft you have the 1.9 too many items
By logging into the game again.
delete the bin folder. =p
If Minecraft opens to a black screen then the mods you have installed are either incompatible with the game or with each other.This can be solved by checking you have the correct versions of your mods installed, reinstalling them and installing ModLoader or Forge.If nothing works then you can simply force update and play vanilla Minecraft.
Reinstall it? And if you're using mods then navigate to .minecraft/bin and open minecraft.jar with winrar or 7zip or whichever you choose, and delete META-INF. this should fix black screen
The black screen means the mods you have installed are either incompatible with the game or with each other To fix this you have to force Minecraft to update minecraft.jar, which will uninstall all your mods: before you log onto Minecraft click Options, click on Force update! and click close and log in as usual