2408WFP, solid green light, no image, can't turn off

Hi.  This just happened to all THREE of my Dell 2408WFP monitors.  I unplugged them all as was building a new computer.  Cleaned them, and now all three as soon as I plug the cord in the power light goes solid green, and thats it - blank screen, cant turn off, buttons do nothing.   

Ive had these monitors for a few years now and theyve been great.  And its great to have them all the same.  But now it appears they are all dead ? I cant believe that my cleaning them would all of a sudden kill them all at the same time ?  

Did you find a solution for your problem ?  Your post is the only one I can find that its the same symptoms : no powerup at all by the montior except for the solid green light.   Please help!

Thank you

Robert