Question No Signal After I Installed Q9400

[Ferwax]

I recently purchased from eBay a used Core 2 Quad Q9400 since it was pretty cheap, buyer had good reviews etc. I got it and it seemed to be on a good condition, also checked a lot about my motherboard's compability if it supports the CPU and it seemed to be fine. I installed it and I don't see any signal on my monitor whatsoever and I wonder what did I do wrong (if I did). I'm struggling with it for days.

These are my current specs:
Motherboard: MSI P35 Platinum
CPU: Pentium Dual Core E5300
Ram: Samsung 2x2GB 800MHz
PSU: Powertech PT-904 500W
GPU: MSI GT 730 LP
HDD: Seagate Barracuda 240GB
OS: Windows 7 Ultimate x64

I updated my motherboard's BIOS to its latest version before I did anything. If more details are needed, please tell me.

Edit: Very unsure if this is the correct thread. If not, I'm very sorry.

 

[rgd1101]

does it work if you put the old cpu back in?

 

[Ferwax]

does it work if you put the old cpu back in?

Yes. It works just fine.

 

[rgd1101]

if you already update the bios and it still doesn't work, it probably the new cpu

 

[Ferwax]

if you already update the bios and it still doesn't work, it probably the new cpu

I checked the CPU on a friend's PC and it works just fine. What else could cause the problem?