NO Video, NO backlight, everything else fine
2006 model A1174, 20" iMac (first Intel).
My machine is in complete darkness. I believe the screen replacement might have been botched.
Everything works perfect when hooked up to another monitor (mini-DVI -> DVI converter, DVI cable to monitor). So, it appears the GPU is fine.
I see a couple possible culprits:
1. Bad LCD ribbon cable - perhaps if this was totally inop the display would never kick on?
2. Bad inverter - here, the backlight would not come on, which is TRUE however I ALSO do not have an image on the screen via the "flashlight" method.
3. Bad mainboard - something on the mainboard is busted in between the GPU and display cable, but not in the line of the rear mini-DVI port.
If I had lost backlight OR video, then this would be a piece of cake, or at least manageable.
Perhaps, #4 could be that TWO parts have failed, perhaps #1 and #2. But that sounds a bit unlikely... but I could see how that *could* happen (say, inverter dies, new screen installed by "mistake", ruins lcd ribbon in the process?)
I'm afraid I might just have to "shotgun"-select parts until something works...
Read the comments below.
I had a panel with revision number/code (or type code???) that corresponded to an older 20" G5 iMac. EVEN THOUGH the main MODEL NUMBER was IDENTICAL, apparently the panel was NOT compatible. Upon purchasing the correct panel, the iMac was fully functional. Again, the details are below!
Short version: order the EXACT PANEL!
Is this a good question?