Imac 2009 i7 video dissapear in 2-3 miutes

[MDY]

Imac 2009 i7 video dissapear in 2-3 minutes. Is that screen problem? If I reboot the iMac video comes again for 1,2,3 minutes each time I reboot. Sometimes 30 seg.
On external screen always has video.

 

[MUUK]

I've had a lot with similar problems. If you've tried replacing the backlight board (661-5311) then it is most likely the LCD.

 

[Gurmon]

Im seeing a lot of these now.

Is anyone here repairing the backlight LED strips in these ?

 

[MUUK]

I've tried taking these LCD's apart, its a ball ache of a job to get to the strips

 

[dukefawks]

Usually the LEDs in the LCD. Rip apart complete LCD and take out the LED strips. If they have the square LEDs you only need to resolder both connectors.
If they have the rectangular LEDs, you also need to flux and reflow ALL LEDs.

It's a PITA but many LCDs have this issue now, also very common on the Cinema displays.