Solved.  It is interesting. this gpu has two dvi ports. if monitor video cable plugged into bottom dvi, no video on post.  Pc appears to work otherwise.  if then hot unplug and plug in upper dvi, still no video. but if video cable is plugged in top dvi cold, then power up pc, after some bios deliberation when it seems to think about it, got video.  If then hot unplug and plug in bottom dvi, no video. installed Win 7.  seems on power up only video in top dvi, but after os launch, both top/bottom dvi show video.  summary: top dvi is default video port of card.  has to use that for pre-boot post video. strange point is if pc detects video cable plugged in non default video port of card (bottom dvi), it would not only refuse to send video to that port, but also disable the default video port as well, giving a double blind gesture. 
A high end 2009 Dell oem nvidia gpu recently tested working, then moved with pc to another location, power up, got no video at all.  No error from pc.  Just black screen. installed a second small amd video card in order to see desktop screen.  Device manager shows Windows detects the nvidia card and automatically installs the correct driver.  This is from the day of legacy bios no UEFI or secure boot then. my question is, there is a small possibility that the card suddenly lost video output over a few days interval but strange that such an event occurred right around time of transit of pc from one place to another.  Is there any other explanation for this sudden loss of video function while the gpu is still detected correctly by Windows?  Video cable/monitor both tested working and I was using same setup to get video from amd card.  Unplug cable from amd and plug it in nvidia gives a black screen no signal.
Dell Nvidia GPU no video output