My D530 will not start up there is just a green

First check num lock key on key bord when u press it numlock led is on and offf.if that led on and off then your cpu is ok then you need to change screen resolution
when you power press F8 key then enter in enable vga mode then go to control panel ->dispaly ->settings then change screen resolution to 1024*768 then aply and ok then restart it.

But if num lock key not onn and offf then you need to open cpu cabinet then reattch all connection to mother bord also reattch connection to harddisk.
Also pull cmos cell for 15 minutes then refix it then all settings of bios are reset to defaults.
then check.
Please rate my solution if you tihnk that i help ful to you.
Thanks for using fixya.