Model A1224 / Mid 2007 and Early 2008 / 2, 2.4, or 2.66 GHz Core 2 Duo processor

585 Questions View all

incompatible TFT panel?

having 2 broken alu iMacs (20" and 24") I decided to make one good 24" out of the two.

The problem with the 24" was 'only' a dead logic board, so I took out the 20" logic board and put it in the 24" (easier said than done).

The problem now is that the 24" TFT panel remains black/has a vague glow. I do have backlight.

An external monitor displays normal startup screens and switches to the purple milky way screen (standard secondary monitor screen) when the 24" panel should show my desktop, which it does not.

The iMac runs well on a 20" TFT panel attached (without backlight).

I tested the 24" panel a year ago in another 24" iMac, and it was allright then. Maybe I have to test it again.

I have a feeling though that there is a compatibility problem between the logic board and the TFT panel.

Is there a key combination to force OSX to switch to an external monitor, so that I can see what I am doing ?

Answered! View the answer I have this problem too

Is this a good question?

Score 0


I noticed you never got an answer to this. Are you still having this problem


Hi Machead3,

the problem is still there where I left it. I'm quite sure that the 20" logic board won't accept a 24" LCD. Although 20" and 24" LCD's differ in resolution, this can't be the reason of the problem, because the video card (ATI Radeon HD2600 Pro) is the same.


Add a comment

Free shipping on all orders over $100 or containing a Pro Tech Toolkit!

Browse Our Store

1 Answer

Chosen Solution

I suspect that if all connections are good what you are experiencing is a firmware mismatch of some type. Maybe Ben can jump in and educate us.

Was this answer helpful?

Score 0


Maybe you are right. But isn't the EFI firmware and SMC firmware the same for 20/24" ?

I did check the 24" LCD panel in another 24" iMac. It was all right as I expected.

I'm sure the connections are all right, because it is all working well with the 20" LCD panel.

The LVDS cable is the same for 20/24" too )besides the length).


Add a comment

Add your answer

Cees will be eternally grateful.
View Statistics:

Past 24 Hours: 0

Past 7 Days: 0

Past 30 Days: 0

All Time: 1,220