If your OS loads from CD only part way (yes, some of us still use discs), then hitting several errors about loading drivers or files…… very often it is a mismatch of Master-Slave relationship on the optical drive(s). CS (Cable Select) option is an easy way to set these up, sometimes…. but some cables and drives just don’t work right together, in this mode.
No video at startup……machine you just worked on not sending display? Often we find this to be a ram issue. While most boards will send error beeps, several models -including HP DX2400 series PC’s- just don’t……. they take a more passive approach, not starting all the way. Check the ram for proper seating and type.
No video after changing video card. Many possible answers here….This is far from a complete checklist, but some of the things to check:
-Used/bad video card? Try a known/spare card.
-Bios setting, making sure the slot you are using is set as an active or preferred video output (which can be done, of course, only if you have video during bios)
-Ram/board not syncing with new card…. try full reset of bios to default. This does NOT only mean taking the CR2032 out. Google ‘bios reset.’ This is more common than you might think.
-Wrong card specs for board/slot. This was a big issue with 4x/8x etc AGP boards and slots.
IF the system has on-board video, please back track, simplify and make sure that feature works.
I’ve seen this problem go from days to weeks. You have your work cut out for you.