820-3115 powers off as soon as J3501 cable is connected.

[arash]

Any idea where to start? power lines are all fine.

 

[dukefawks]

You're not supposed to plug that in with the board on. Does the board power on with it connected? If not first try a know good cable and airport card.

 

[arash]

The board turns on with it connected and after 10 seconds turns off

 

[dukefawks]

Did you try a known good cable and airport?

 

[arash]

Sure, of course.

 

[dukefawks]

Does the screen come on before the board shuts off? Did you change the cable and airport card both at the same time?

 

[arash]

Yes changed both, the screen comes on before it turns off

 

[dukefawks]

Remove U3540 and see if stays on.