Hi - there are more hidden screws so you need to undo those:
- Where the stand joins on the back, there are two plastic bits either side of the pivot. They don't look as if they come off but if you squeeze them (squeeze top and bottom) then they unclip.
- Remove the 4 metal screws you have just revealed (2 each side)
- Remove the 4 larger metal screws holding the stand to the monitor
- Remove 1 metal screw that you have just revealed which was hidden by the metal plate on the stand holder.
- Use a straight-bladed screwdriver to create a gap at the bottom of the monitor between the silver front / black back of the case.
- Open this up all around, and remove the silver front - undo the multi-cable connector which connects to the operating buttons and put the silver part to one side
- Lever out the monitor chassis.
- Put the LCD face down on a table but make sure there is nothing underneath it (I have two black blobs where mine sat on a bump in the table!)
- Then open up the cage with the electronics in it, by undoing 2 screws and sliding the cage off.
- Remove the four screws holding on the power board (the big one with a mains connector, disconnect any connectors, and then remove the board.
If your monitor is not working (even if the power light is dead), check for swollen electrolytic capacitors (tall things with an x at the top, made of metal with plastic around them). If you have swollen ones, that's probably why the monitor doesn't work. Replace them (make sure the + and - sides are in the correct places when you replace) and hopefully your monitor should work.
If it still doesn't work, look for any heat damage and poor soldering.