Monitor taking ages to wake up.

[Barrymore]

Agreed, open up and check for capacitor that is bulging at the top. Replace with one with similar Voltage and same or higher capacitance. (Caps are polarised, take note)

Likely to be an easy repair for anyone capable to operate a soldering iron

Not so easy. There are no screws holding the thing together. One has to use a knife to prize open the casing from the screen.
I have tried that but all it does is damage the plastic casing.

UPDATE: I finally got the board out. There are no signs of any of the six capacitors being "bloated"
So this must be the end of the line for this monitor.