Ok lets try a few simple things?
Firstly pulling the cord is not a good idea it causes hardware damage.
Lets try a few simple things.
While powered off remove BIOS battery for one minute then replace reboot.
See if that works.
Next disconnect hard drive and remove all
RAM.
Put one stick of
RAM in and reboot see if you get post screen.
Then remove that stick and put in another and reboot do this for every stick you have.
If you do get the post screen can you double check your BIOS setup?
Make sure all PCI cards are connected and pushed in fully.
Possible problems :Error Tone. (two sets of different tones)Problem with logic board or SCSI bus.
Startup tone, drive spins, no videoProblem with video controller.