Dell optiplex 990DT wont boot after cpu upgrade

[nishilamin1213]

i bought a used dell optiplex 990 DT and 4gb of ddr3 compatible ram. after testing it (preinstalled i3 2nd gen LGA 1155) i added the ram, it still worked fine. today i replaced the intel i3 2nd gen with an i7 3rd gen fitting the correct socket. now it won't boot and the motherboard beeps once.
please help about how to fix, its my first cpu upgrade

 

[rgd1101]

http://i.dell.com/sites/doccontent/shared-content/data-sheets/en/Documents/optiplex-990-spec-sheet.pdf
only said support 2nd gen

http://www.userbenchmark.com/System/Dell-OptiPlex-990/578

just because it the same socket doesn't mean it will work.

 

[ThatVietGuy]

I'm guessing the OEM motherboard doesn't have the proper BIOS to support the newer CPU.

According to this, it only supports 2nd gen Core i3/i5/i7 processors - https://i.dell.com/sites/doccontent/shared-content/data-sheets/en/documents/optiplex-990-spec-sheet.pdf

 

[nishilamin1213]

http://i.dell.com/sites/doccontent/shared-content/data-sheets/en/Documents/optiplex-990-spec-sheet.pdf
only said support 2nd gen

the mobo does support lga 1155, so do i need to return and buy new processor

 

[nishilamin1213]

I'm guessing the OEM motherboard doesn't have the proper BIOS to support the newer CPU.

According to this, it only supports 2nd gen Core i3/i5/i7 processors - https://i.dell.com/sites/doccontent/shared-content/data-sheets/en/documents/optiplex-990-spec-sheet.pdf

thanks, and i'm assuming i can't update bios, so i'm stuck to replacing cpu again

 

[nishilamin1213]

I'm guessing the OEM motherboard doesn't have the proper BIOS to support the newer CPU.

According to this, it only supports 2nd gen Core i3/i5/i7 processors - https://i.dell.com/sites/doccontent/shared-content/data-sheets/en/documents/optiplex-990-spec-sheet.pdf

thanks, and i'm assuming i can't update bios, so i'm stuck to replacing cpu again

 

[rgd1101]

http://i.dell.com/sites/doccontent/shared-content/data-sheets/en/Documents/optiplex-990-spec-sheet.pdf
only said support 2nd gen

the mobo does support lga 1155, so do i need to return and buy new processor

Same socket doesn't mean it support it, require bios/chipset support too

 

[ThatVietGuy]

http://i.dell.com/sites/doccontent/shared-content/data-sheets/en/Documents/optiplex-990-spec-sheet.pdf
only said support 2nd gen

the mobo does support lga 1155, so do i need to return and buy new processor

Obviously, yes.

You can use second gen i3/i5/i7 processors ONLY.

 

[nishilamin1213]

I'm guessing the OEM motherboard doesn't have the proper BIOS to support the newer CPU.

According to this, it only supports 2nd gen Core i3/i5/i7 processors - https://i.dell.com/sites/doccontent/shared-content/data-sheets/en/documents/optiplex-990-spec-sheet.pdf

Thanks; so i'm assuming i can't update bios to a compatible one so i will have to re-install old cpu

 

[nishilamin1213]

Thanks All; i have managed to switch to the old i3 and all is well, i'm really grateful for the quick and accurate resopnse and will return or resell the i7-3rd gen and buy the i7-2nd gen. Sorry for any inconveniences caused or time lost!