here's the deal: if you hear no beeps, and there is no monitor signal, there is a very good chance that your cpu doesn't start up.

This can be for any number of reasons, ofc it can be a DOA, but also, it could be lack of power (unlikely, with a 750w psu) or - your mainboard doesn't support it, with the current firmware/bios

How to progress, if it were me: resocket the old cpu, reconnect stuff and see if you can boot up. If so, go online, find your mainboard and download the latest bios/firmware. Then upgrade it, and check that it works. Also read the releasenotes, to see if anything is mentioned regarding your new cpu.

Next, resocket the new cpu, and power up.

If it still doesn't work, try disconnecting all peripherals, like harddrive, cdromdrive, cardreaders and what have you. All you need connected, is mainboard, graphicsadapter, ram, cpu and frontpanel (to be able to click the power button ). Any other pci-e or whatever cards like soundcard, yank it out. If it still doesn't start, you should contact your retailer, and ask for a new cpu.

Good luck