Boot Issue - Compaq Presario 4540

Hello All,

I am hoping that someone out there may have some experience with the
following issue: I maintain several Compaq Presario 4540's at my place
of employment. Two of them now have completely "died"... There is
absolutely no video display. You cannot boot at all, even from a
diskette. You cannot go into the setup config either. The incorporated
video is obviously failing, but is this the real issue or just the
result? When you boot the computer, the hard drive and CD-ROM are
accessed temporarily. However the monitor light never turns
green....and that's about all you get! I've tried removing cards (NIC,
modem, etc...) to narrow down the possibilities. I've also tried a
known good video card. Any thoughts? Thanks for any response, in
advance!