How do I find the right cpu?

[no-name]

I bought a Dell Dimension E520 for very cheap and I wanted to upgrade the cpu and bought a Intel Core 2 Duo E4800 to replace the Pentium D in the system. I checked the socket type before buying it to make sure it fits. Once I have installed the cpu in the computer and turned it on I was presented with nothing, the fan was spinning slow and the screen did not display anything just like when I installed a mobile cpu into an old computer. I looked everywhere to try to find out why this computer did not recognize the cpu, even updated my bios but it still doesn't work. can someone explain to me how do I chose the right cpu? (what should I look for other then socket type so it matches the mobo) *also the computer recognizes the Core 2 Duo E6300 just fine but not the E8400

[LienusLateTips]

You have to stay with that generation. There were kinda like 2 generations of LGA 775. Pentium 4/D and Core/Core 2. Most of them aren't intercompatible. You have to get a different Pentium D, not a Core 2.

[Jurrunio]

Socket 775 is a confusing platform. You have to buy a CPU with the same / lower FSB in order for it to work.

[LienusLateTips]

Just now, Jurrunio said:

Socket 775 is a confusing platform. You have to buy a CPU with the same / lower FSB in order for it to work.

in addition to that stupid chipset problem

[no-name]

On 8/13/2017 at 7:09 PM, Jurrunio said:

Socket 775 is a confusing platform. You have to buy a CPU with the same / lower FSB in order for it to work.

So the generation doesnt matter at all? as long as the fbs is the same?

[Jurrunio]

5 hours ago, no-name said:

So the generation doesnt matter at all? as long as the fbs is the same?

FSB usually changes with generation, so most of the time they mean the same thing. In cases which generation progresses but FSB remains, then there's a chance that old motherboards support it, but no guarantees.