I recently bought a Celeron 1.2 Ghz chip. When I install it in a new Chaintech motherboard rated up to that speed, nothin happens. The cpu fan spins, but no boot up. No beep or video. I plugged in my old 677 Celeron and the system booted fine. What am I doing wrong???

What model number is the Chaintech motherboard?

it's a chaintech 6vjd via pro266 socket 370 motherboard

Ya got me. Make sure you're on the latest bios though...

http://www.chaintechusa.com/Downloads/MBBIOS.htm

Is it a 1.2 or a 1.2 A or B??
cuz those wont work on a regular old socket 370 board...ive never even heard of a 1.2 for a socket 370...i would have gotten one for myself hehe

You are out of look Celeron 1200 processors are Tualatin/FCPGA2 0.13u ones. Your board has a chipset that only supports old Coopermine/FCPGA 0.18u processors (the most fast Coopermine/FCPGA Celeron is the 1.1 one, but Tualatin ones are available from 950Mhz. I think). You cannot use that CPU with your board. Either try to find a Coopermine/FCPGA Celeron or change your board with another that supports Tualatin/FCPGA2 CPUs.
Coopermine/Tualatin CPUs are very easy to diferenciate. To see how the different Celeron cores look go to the botton of this page:

http://www.tomshardware.com/cpu/20020103/index.html

It's a pity the Celeron 0.13u ones are very good to overclock. Take a look at this article also:

http://www.tomshardware.com/cpu/20011003/

Celeron 1200 runs smoothly @ 1500 and performs very well.

where did you read that your board supports up to a 1.2g celeron?