|Remove all cables, especially the power cable from the monitor. Get yourself a can of WD40. Squirt a little around the switch. Go and do something else for an hour then come back and see if the button has freed itself. If it is still stuck, get a thin bladed knife and try and wiggle the switch out. If to comes out, squirt a little more WD40 around the switch, wiggle it about a bit then carry on with what you were doing before for another hour.|
Once you are certain all the WD40 has evaporated, connect the cables and turn the monitor on.