HP elitebook 8460p Won't Boot After CPU Upgrade

[ThatOneName]

Hello, I currently have a Hp Elitebook 8460p. I wanted to upgrade my CPU in the laptop so I did so. After going through the list of supported CPUs found here. https://web.archive.org/web/20170630043843/http://h10032.www1.hp.com/ctg/Manual/c03253774.pdf 

Goto page 1

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It says the 8460p supports an i7-2760M. So I bought it off of eBay and put it in my system. But it didn't work.

It turned on for 5 seconds then turned off nothing on the screen.

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Things I tried: Updating BIOS

unplugged the CMOS battery and held the power button for 30 seconds

plugged the laptop into AC power    

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When I put the i5-2520M the laptop booted up into windows 

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The system has an i5-2520M originally inside. 

[banhien]

@ThatOneName 

The list for i7 processors (CPU's)  (page 94 of the shown manual)

Intel Core i7 processors, Quad Core
2860QM, 2.5-GHz (turbo up to 3.6-GHz) processor with 8-MB L3 cache  part #  666175-001
2820QM, 2.3-GHz (turbo up to 3.4-GHz) processor with 8-MB L3 cache part # 634694-001
2760QM, 2.4-GHz (turbo up to 3.5-GHz) processor with 6-MB L3 cache part # 666174-001
2720QM, 2.2-GHz (turbo up to 3.3-GHz) processor with 6-MB L3 cache part # 631254-001
2670QM, 2.2-GHz (turbo up to 3.1-GHz) processor with 6-MB L3 cache part # 665116-001
2630QM, 2.0-GHz (turbo up to 2.9-GHz) processor with 6-MB L3 cache part # 635501-001

Intel Core i7 processor, Dual Core
2640M, 2.8-GHz (turbo up to 3.5-GHz) processor with 4-MB L3 cache part # 666173-001
2620M, 2.7-GHz (turbo up to 3.4-GHz) processor with 4-MB L3 cache  part # 631252-001

Which part # did you buy from eBay ? It is VERY important to buy a right part #.

Regards.