Hi,
Your Sun GDM5410 has an analogue input whereas your NEC LCD 1980SX has a
digital input. Whether or not you can get your Sun monitor to work on your
system depends on whether your system is capable of supplying the requisite
signals. I assume, that since you state that the monitor is working with your
XP machine that you are using an analogue interface on the graphics card with
that machine. Back to your Vista machine. You state that your NEC monitor
works correctly with the DVI interface. I provide a link to the 'Digital
Visual Interface' page in Wikipedia to give you further information.
Basically, not all DVI interfaces are created the same. Only the DVI-A and
DVI-I versions carry the analogue signals. Since most (if not, all) graphics
cards have 2 sockets, you can try using the other one to see if you can get a
signal from that. Of course, if the graphics is built-in to the motherboard,
you will not have that option. As the sockets themselves are relatively
cheap, it is possible that the motherboard manufacturer has used the
universal DVI-I (Dual Link) connector with only the digital pins connected.
Dwarf
http://en.wikipedia.org/wiki/Digital_Visual_Interface