I just attempted to build a custom PC, and installed a DVD-RW, CD-RW, and 2 HDD's, and when I plug the power in, it comes up on the monitor "No Input Signal," and I've tried all of the options, and I have an on-board graphics card, and I just installed another graphics card.
More about :installed dvd hdd monitor input signal
It can be that your PSU is not big enough. I take it that the monitor lead is hooked into the new card and that the IGP is disabled.
If you post your full system specs then it easier for us to help you.