After G73jw motherboard replacement, power button does not turn on PC

I broke the speaker socket on the motherboard when attempting to dismantle the machine for fan cleaning.
Replacement board through AliExpress (Chinese Ebay...sort of) claims to have been 'tested'.
Swapped boards.
Applying 'fixmykb' fixed the absence of keyboard backlighting. Reinstalling the OS fixed the wired/wireless LAN and bluetooth problems. But since the swap, the power button will not turn the computer on. I can get the machine running though.

The power button works when the computer is running but it does nothing when the computer is off. To turn the computer on I must go through ExpressGate (second button from the left, beside the backlight button, also acts as the 'Turbo' button).
I wondered if anyone had heard of such a problem and whether anyone had a solution for it.

Thanks.

 

It could be the ribbon cable is not quite seated right.

 

Thanks for your reply.

Which ribbon cable might that be?

 

I believe it's one of the ribbon cables under the keyboard that will go from the power button to the motherboard.

 

I didn't open up the machine and try to reseat the ribbon as Meaker suggested.
But I might have found a solution to my problem. So I'll share it in the event that somebody wih the same problem finds the original post.
I reinstalled the other OS (dual-boot system here) which is Linux Mint 17. I think the Windows 7 MBR was replaced by the Linux bootloader. After that the power button began working.

I hope this helps someone out there.

 

The software on the machine really should have no impact on the power button when it is off, if it comes back then I would check the cables.