That's a nicely basic and thorough video hitting many important parts. Hopefully, anyone watching for instruction will be sure to note the disclaimer that some mobos are NOT to be powered up while the jumper is in the "Clear CMOS" position. This is why it is always good to discover the make and model and get the tech manuals from the manufacturer.
So here's the updated recommendations:
1) Remove the ram and attempt to boot (it won't) to ascertain if you have a speaker connected that is beeping error codes and/or to see if there are any LED or LCD readouts that flash codes. If there are no beeps or flashes then the CMOS battery is dead or too weak to work, as noted in the above video B.Elliot provided.
2) If there are none, signifying bad battery, replace it. If this is difficult sometimes leaving it powered up for a few hours, even though nothing seems to be happening, will recharge it. AFAIK all mobos use a 3.3v CMOS and battery to power them, so these are interchangeable on the vast majority of mobos, so substitution may be a possibility.
This is the first step because Beep Codes do not require any external hardware to the base mobo - no cpu,gpu, ram, etc. The beeps are like Morse Code in that (a bit unfortunately for repair guys) each manufacturer creates a code database for specific series of CMOS/BIOS and these point to what is not working. That's why when, for example, the ram is removed, you should get a coded sequence telling us exactly that.
Once the beep codes are available, re install the ram. power up and now you should get a different sequence assuming no graphics card is installed. Then install the graphics card and cross all your fingers and maybe wave a rubber chicken over the system and chant "Oh Gods of the PC Subconscious, breathe life into this humble servant so it may toil for it's Master", ... or at least that's what I do when I'm feeling spunky :)
All kidding aside, unless some serious damage has occurred (and the fact that it displayed "green lines" <at least something> leads me to believe this is unlikely) the system should now display and function properly once CMOS/BIOS settings have been set properly.