Hi
My 19" MAG LCD monitor does does not display anything. After boot up, it displays for a few seconds and then goes black; the same happens when I switch the monitor OFF and then ON. The problem has got nothing to do with system unit because when I connect a different monitor, it displays fine.
What might be the problem with my monitor and how can it be fixed?

Cheers!!!!

Does it switch into standby mode or does the green light stay on?

It most likely has a dried out capacitor in it as this is a very common fault.

If you wish to repair it yourself you will need to open it up (which is no easy task to do without breaking one or more of the clips that hold it together) and identify and replace the faulty capacitor.

If you wish to fix it I will be happy to help. I have repaired upwards of 100 LCD monitors myself.

The green light stays ON

That means the fault is most likely not to do with it's built in power supply and is likely to be on the main board. It is till likely to be a capacitor though!