The beeps are proper for the removed parts so don't panic.
Since it still power cycles my diagnosis given the story so far is it's the motherboard or the power supply with a 60/40 chance it's the PSU (power supply unit.)
Again, no screen and beeps is proper with those parts removed so all I can ask is for the make, model, age of the machine to help diagnose it further.
This is what first happened, I was using it and it just suddenly powered off and tried to power back on, but would only do so for a few seconds before starting the whole process again. It started POST, but never lasted long enough to load windows.
I did some research and disconnected all RAM, hard drive, dvd rom, card reader, and tried to boot again. Now, I get a series of long beeps and the power cycling. Nothing on the screen. Help.