I installed a new mother board and now I have no MONITOR. nothing will come up it wont even power up. Is there something I have to do? Is your boad in a case or out of a case?Tell us what you did...step by step.board is in the case. what I did is removed all cables leading to the tower power,mouse etc. Opened the case and wrote down the color coded wire bundles that go to the mother board so I know where they go on the new board. removed the additional cards for the WIFI and the video card and the sound card. removed the memory then removed the motherboard. REPLACED in the reverse ORDER. went to turn on and now I have no monitor. I looked in the back at the ABCD lights. The ABC is yellow and the D is green. According to the Dell book this is a Bios problem. Cant run a disk because I cant see what is going on with a black screen on the monitor. Did you take anti-static precautions while working?

Does the computer get any power?

You power supply may have an on/off SWITCH on the back. Is it turned on?

Have you tried plugging it into a different outlet?

Have you checked your motherboard book to make sure that you have the power connectors in the right place?

Are all of your motherboard standoffs in place?

Check your power switch connector.

Try using a screwdriver to short the power switch pins. If according to dell its a BIOS problem then try flashing your BIOS by looking in the instructions for the motherboard.