CPU upgrade didn't work

[AlexC1981]

Hi All,

I'm assuming I've bought a duff used processor from eBay unless anyone knows of a reason why the upgrade might not have worked?

The laptop is an HP DV7-4180ea with a i7-720QM CPU. The replacement is an i7-840QM.

It's on the latest F.29 bios and the 840QM is listed in the maintenance manual. I cleared the CMOS after I installed it by removing the coin battery and all other power sources, and holding down the power button. Then left it for a few hours.

When I press the power button the fan whirs and the power light comes on for about half a second. Nothing on screen. No beeps. I have since reinstalled the old CPU and it works fine.

I think I have done everything right, but just wanted to make sure I wasn't missing something one of you clever techies would know.

Manual
http://h10032.www1.hp.com/ctg/Manual/c02666747

720qm Intel web page
https://ark.intel.com/content/www/us/en/ark/produc...

840qm Intel web page
https://ark.intel.com/content/www/us/en/ark/produc...

[anarki]

Sounds like you know what you're doing and I would assume the same as you - CPU is faulty.

I could test the chip in my portwell Wade qm57 motherboard for you, but that means you sending it to a randomer on the internet and you paying postage to/from me.

I would just return it to the seller stating it's faulty if I were in your shoes.

[Robert_Snow]

Maybe the whole problem in the BIOS version of the motherboard

[AlexC1981]

Thanks for the advice and kind offers chaps. The seller has refunded me today. I can't see why it wouldn't work unless it was faulty. I looked up the model number of the model of my laptop that came with the 840QM factory fitted and the latest bios file for it appears to be the same one I downloaded.