Computer turns on but does not show on screen. HELP!?

NO! First check if the PC speaker is plugged in, this is a very important little thing.... now, when you start up, you can hear a quick beep, if its a quick beep then everything is okay... but in your case, im sure you're gonna hear 3 long beeps... Which mean faulty ram pop in one at time, and single out which one it is.

Does your motherboard support that RAM in terms of Size(what is the maximum amout supported by your motherboard?), Type(DDR2, DDR3), Frequency(667MHz, 1066MHz, 1333MHz). First of all, ensure that it's supported by your motherboard, as they may have limitations. Also, Some motherboards are dual channel, some are tri-channel. Is 16 gb in single slot or multiple slots? some motherboards supports limited ram in single slot. For example: my motherboard support only 4GB ram per slot. If you are installing in multiple slots, check for dual channel or tri-channel or even- quad channel and you need to install in proper slot for which you have to refer to your motherboard manual. I hope this helps :)

Check the simple stuff first. Is the monitor plugged into the power? Is the power on the monitor switched on? Disconnect the connection to the monitor and to the computer and reconnect them to make sure the video cable is not loose. Reboot the computer. power the monitor up and down. Those are simple steps that maybe 50% of the time are the problem.