This is a common problem across many monitors, unfortunately. The problem stems from one of two things, typically.
It is either the Power Inverter board (Inverter Mirage Electronics AD-1700 Rev:F 200-000-170DTL1 VERSION:A) or a weak or dying backlight.
your monitor comes on for 2 seconds then you can test the backlight by
using the controls to get into the backlight brightnes settings on the
OSD and turning it WAY down.
If that dosen't work then it is
likely bad capacitors on the Power board mentioned above. If you feel
adventurous and know how to solder then you might be able to fix this
yourself. You need to be careful however because you are dealing with
high votage in there and capacitors CAN hold a charge long after you
have unpluged the unit. You can read more about this power board as
well as how to replace the bad caps HERE
that's not for you then I would recomend taking it to a local TV shop
for them to fix. The parts shouldn't be more than $20, but labor can be