Symptoms of many beeps is frequently video problem. The AGP slot has a lot of friction for inserting the Video card. [many contacts]. Try reseating the card.
If you followed Robert's instructions you would isconnect power and signal, all cards and get to bare bones.
In April, I refurbished a not too old computer with new guts. A P4x400 Soyo light MB, Intel Celeron 2.6Ghz w/128cache 400fsb chip set, Ultra 256 MB memory PC2100 266Mhz, new fan, larger powersupply, Nvidea video card, and also a larger Hard Drive. Last Sunday everything quit. Turning on the computer, it checks both CD Rom drives, beeps.....................beepbeep, communicates with the floppy drive, and that is it. Power LED remains on and HD LED soon goes out, but nothing else.
In the meantime the monitor remains in limbo. The monitor LED starts up green and then switches to amber. Computer will not boot from a startup disk, nor can I access the BIOS. I have checked both 5volt and 12 volt and they are ok. I had indications of pending trouble earlier as sound waves were distorted and video went bonkers a couple times, also some times I could move the mouse pointer and it would be several seconds before the image on the screen followed. I don't think that high temperature was a problem as I could place my fingers on the CPU heat sink and it was only midly warm. (after powering down, of course)
I have tried Bob Proffit's suggestion to "Boot Problems", removing power from both CD's, HD, and Floppy. Also connecting to another monitor. Results were negative.
As previously, I really appreciate your support. Thanks