iMac 20 2009 LCD issue

[lugo]

Hi Bunch ,
there is iMac 20inch 2009 for repair . No LCD , no 4-ty light test diode.
Model is k50 820-2347-A , I found a line PPMCPCORE_S0_REG short to ground.
When I desolder U7401 nVIDIA , short conection is disappears. Put new u7401 IC and short conection is here . Check all capacitors around -OK.
Any ideas is welcome.

Kind Regards
Lugo

 

[jji7skyline]

Swap out the logic board?

 

[lugo]

It is a good ideal, would cost me £ 165.
Regards