sounds like no signal/no power to me , the monitor mains feed should be fused as it uses straight mains unlike the dc voltage the PC will use.
Open her up and get yr meter out and check the mains in it should split somewhere in the case one will go to the psu for the motherboard the other will feed 240v straight to the monitor depending on the setup the fuse will either be just after the split or on the monitor chassis itself.
HTH