I have a monitor that used to work fine, but now when the
computer starts up, the monitor switches off immediately,
without even showing the bios screens. If I unplug it from the
computer it shows the "signal not found" screen fine. Once I
plug it in again, it switches off immediately.

The monitor is a LG Studioworks 700S. I tried it on other
computers and it showed the same behaviour. It's out of
warranty, is there any hope of getting it fixed?