For the first time ever i unscrewed my computer, i wanted to vacuum all the dust out. Once i got inside the machine i took out the 2 fans, the RAM, and the hard drive, and unscrewed the power supply box but didnt unhook anything from there. Once i finished i reconnected everything and tried to turn on my computer, but nothing was showing up on the monitor. The computer starts normally, there's a green light inside of it so its getting power, the monitor says "test good" whenever i test to see if its working. I've also already tried plugging my monitor into the motherboard port as well as its default port. Can anyone help?