my screen has gone very dark, I have tried all the usual stuff to try and a?

If you can just about see the information on the screen, but it's all just very dark, you probably have a failed back light inverter.

You didn't bother to mention what make/model computer or monitor you have, but you do talk about "removing the battery", which suggests a laptop.

You could do worse than Google for your model of laptop and the word "inverter", which may suggest whether other people have had problems.

It may also suggest likely solutions.

Edwin
January 2010