Cause of blank screen, otherwise normal operation?
I suspect the display has died but does anyone have any suggestions on things to check to fix an imac screen?
The diagnostic LEDs are showing
1. Lit when connected to the mains
2. Lit when machine is running
3. Lit when machine is running
4. Not lit when on or off.
The machine starts and runs and outputs to an external monitor but its internal display is completely dead. No backlight or anything.
This occurred after a failed hard disk was DIY replaced, the mainboard to display cable was damaged and replaced during this operation - is there a way to test the display or confirm that a particular component is defective in the chain? The mainboard display connector seems ok, all its pins look visually ok, the vsync lead is ok, the temp lead also ok and the power (I think) lead from the
video adapter inverter is also ok.
Be good to know where to investigate even if its only to know which bits cannot be sold on as spares. I'm perplexed as to the display led #3 reporting that its ok even though its not showing a picture, unless the picture is being sent but the display isn't powering up to show it?
I'm testing it without a hard drive in case this makes a difference. I do get the start up 'chime' and I've reset the pram and pulled the cmos battery (2.9v) and left overnight. But to no, unsurprising, effect. Its an a1311 model.
Any pointers appreciated,