You never mentioned what operating system you used.
As you used another monitor more than likely the settings for this monitor in relation to the graphics adapter means the 15 inch monitors specifications cannot handle the current settings.
First allow it to go into safe mode, and if it was a windows XP machine then right click on the desktop select properties then settings and left click on the advanced button.
select the monitor tab and make sure under monitor settings that the box is ticked for to hide modes that this monitor cannot display, above you should also see the refresh rate in Hz.
You may have to lower the refresh rate if it is to high remember not to go lower than 6oHz as you are liable to get headaches
You should then OK and OK again this will bring you back to the desktop.
Reboot the computer, this should allow you to go into the normal bootup, once in you will need to change the resolution as safe mode changes automatically to min resolution. This is achieved by going into properties as above but select settings and change resolution, best to do small changes if you dont know the monitor spec.
If this does not work you may have to get drivers for this monitor.
Athollman, June 2010
