what happens when i press the power on is that the cpu light flashes, then the ram led stays on for a second, then the cpu led flashes again, then the ram led says on for a second again, and then the system shuts off for 2 seconds, and then the computer turns on again. this cycles indefinitely.
could the problem be that i'm missing a gpu or something wrong? I could make a video to help you if you need it.
Make sure that all of the power connectors are connected to where they should be and that any excess connectors are out of the way. Also, be sure that your CPU is seated properly (and check for bent pins in the motherboard and for damaged lands on the CPU's underside) and do the same for your RAM.
If it still won't POST after you do this, then get a can of compressed air (make sure that it is rated for usage on electronics). Unplug everything and blow the compressed air on all of the plugs and slots (using it as directed by the instructions on the side of the can). Then, put it all back together and try getting it to POST again.
Also, check your manual and make sure that the RAM modules are in the proper RAM slots.