27" 2009 imac a1312 inverter problem

[tipoti]

hi,

i have A1312 ,the device is working but goes to sleep when opening

( invertor to lcd ) 4 pin flex cable burned i change it but nothing has changed

No voltage at all 4 pins I couldn't find the schematic what should I do

 

[2informaticos]

No schematic available.

"goes to sleep when opening"
Can you be more explicit; when open what?