Do i need to replace my CPU?

For $20 I guess it can't hurt, but are you sure its the CPU. CPU's do not really fail too often. Is it a continuous beep or does it beep a few times and stop? Usually a continuous beep means a stick of RAM is loose or bad. If the CPU is bad it will usually just not do anything.

Edit
Beep Code troubleshooter
http://h10025.www1.hp.com/ewfrf/wc/document?lc=en&dlc=e...

its 9 beeps, then a 2 sec. pause, then the beeping and stopping continues until I power it off. No fans spin, and the mobo light for power is on and green.

I would google beep codes. Might be memory

Already did that, it was my first try  .

Can you try resetting your CMOS? Pull out the little battery for a minute, stick it back in, reset the date, time, and everything, and see if it works.  

You'd be surprised how often that works. I doubt it, but it's worth a try... doesn't sound like it's your CPU, really. Probably the motherboard... mine went out in pretty much the same way. It just starts going bad, and continually gets worse until it refuses to do anything at all.

i just bought a new mobo and cmos.