PC makes beeping sound after I messed with CPU
Ok, so I know what I've done is kinda stupid, but I'm a noob at hardwares so it just happened lol. Here is my problem: I opened up my pc today to clean it a bit. I'm 100% sure i haven't moved anything and haven't touched any important parts of the chips and stuff when doing it. Except for one of the fans, I removed it to be able to remove the dust. There's been some panel under it that i got curious about (I didn't know it's the CPU), and just removed the cover and took out the processor lol. After taking a look at it I put everything (including the CPU) back the EXACT same way it has been before, plugged in the power cable and tried to boot the system. But now all it does is making a steady beeping sound (short beeps, it ends when i switch off the computer), screens are black. The fans are working though.
So I suppose this problem is related to the fact that I messed with the CPU, but I swear I've put everything back the way it was before. Please, if anyone knows a solution for this problem, help me.
My CPU is an Intel Core 2 duo E4500.