Infinate reboot on late 2009 i5 imac

[tomcom2k]

I switched from the bundled 1TB HDD to an SSD when i got the machine.

I came to sell it last month and went to but the hard drive back in.

I pulled off the internal DP connect

So I ordered a new Logic Board

Installed the logic board.

Turned it on, gets to Apple logo and turns off (then reboots).

Bootcamp boots and run fine.

Is there something I'm missing or is it a faulty logic board?

 

[tomcom2k]

No-one had anything like this?

 

[Adam552]

I'm guessing the EFI is out of date for the OS installed on the hard drive. But I'm not sure.

Reinstall OS?

 

[tomcom2k]

Not even the MacOS install disk reliably boots.

As I said bootcamp from the previous install works fine