New CPU, monitor won't turn on

[Whizkid]

Just bought a Intel Core 2 Duo E8400 Socket 775 and installed it in my computer. I tried booting up my computer, but my monitor won't turn on.

Everything turns on, and sounds like it's booting up, but I don't get a display.

Any ideas?

 

[Tmagic650]

Are you using on-board video or a PCI-e video card?

 

[rpgjohn]

Oh wow! I have the -exact- same processor and the exact same problem. I upgraded from a dual core pentium d 2.8ghz 800mhz fsb, overclocked to 3.3 and thought it might have been the lingering overclock settings that might have been affecting it, so I cleared the bios via jumper but no change, the monitor still never comes on. What motherboard are you using? It's possible I might need to put the old processor back in, update the bios, and then try again... The spec page for my mobo says I need a bios upgrade and I can't remember whether I ever did that. Ugh, I hope I don't run out of thermal paste. I'll post back either later tonight or on the weekend when I have time to try it. You should look up your motherboard and see if you're in the same boat or if your mobo doesn't support the 45nm processors.

Here are my specs:

mobo: p5n-e sli
video card: 8800 GT pci-e, no onboard video
ram: 4 gigs across 2 slots of mushkin
sound card: creative x-fi platinum

 

[DaMak420]

try clearing the CMOS. If that doesn't work, swap the old CPU back in and see if it fires up.

Notice if when you fire up the PC, if the graphics card actually starts up. for example, if it has a built in fan, does the fan fire up? or do the lights just change colors.

 

[rpgjohn]

Also, I don't think I made it clear that the specs for the p5n-e sli don't just mention a bios upgrade, but one specifically for 45nm support. I surfed around on google and found a couple instances of other folks having the same problem and fixing it by updating their bios. Unfortunately I also found some folks with the same problem that had nothing to do with a cpu upgrade or bios upgrade.

As a side note I believe that neither my keyboard nor mouse turned on like they usually do when the computer boots, which was consistent with other reports of an unupgraded bios no-monitor-turn-on-after-upgrade occurence.

I don't think this is a video card problem, I think my video card was running fine and I remember having similar problems with fooling around with overclocking on my last processor when I pushed the clock too far and the monitor wouldn't even turn on until I reset the cpu settings. I mention this because it supports the possibility of the problem being caused exclusively by the cpu.

Whizkid, please let us know what motherboard you have. Depending on that, I would expect you will either need to reinstall your old cpu to update your bios before going back to your new cpu, or if 45nm isn't supported at all by your motherboard you may need to look for a new motherboard. Let us know though, and I'll give you guys an update when I have a chance to try it myself.