No Video To Internal Or External Display .. Please Help!

Hi iFixit Gurus

Got an interesting issue. I'm in the process of clearing out all my spare parts and have found 10 Logic Boards from Mid 2010 Unibody 2.4ghz Core 2 Duo Macbooks.

Using a confirmed working Display cable and LCD panel to troubleshoot, I have found that all 10 logic boards have precisely the same problem.

None of these logic boards have had liquid damage- indicators are white and no visible damage can be seen on the board itself.

When I connect the CPU Fan , memory , hard drive ,charger and LCD , I am unable to get any video output on the LCD (Even though I know that both the panel and the cable are fine as I tried it with a known-working logic board and they worked without a problem. (I'm not connecting these boards to top cases , just using the power button bypass to start them)

Using a Mini DisplayPort >> VGA adapter connected to an external display doesn't do anything either.

Just get the fan spinning up very loudly ...nothing else till I switch it off.

Anyone have any ideas before I throw them in the bin? I find it odd that all 10 have exactly the same issue and would LOVE to get some of them working again for refurbished units.

Cheers!