# Half my display is a big black bar



## hopelesswreck (May 4, 2012)

Everyone,

I need some help here. I am assuming my video card went out on my iMac but I am not sure what to do. 

Can someone recommend how I can get a card and do the installation? I have never cracked open an iMac before. 

My specs are as follows:

ATI Radeon X1600:

  Chipset Model:	ATY,RadeonX1600
  Type:	GPU
  Bus:	PCIe
  PCIe Lane Width:	x16
  VRAM (Total):	128 MB
  Vendor:	ATI (0x1002)
  Device ID:	0x71c5
  Revision ID:	0x0000
  ROM Revision:	113-xxxxxx-139
  EFI Driver Version:	01.00.139
  Displays:
iMac:
  Resolution:	1440 x 900
  Pixel Depth:	32-Bit Color (ARGB8888)
  Main Display:	Yes
  Mirror:	Off
  Online:	Yes
  Built-In:	Yes

Hardware Overview:

  Model Name:	iMac
  Model Identifier:	iMac5,1
  Processor Name:	Intel Core 2 Duo
  Processor Speed:	2 GHz
  Number of Processors:	1
  Total Number of Cores:	2
  L2 Cache:	4 MB
  Memory:	2 GB
  Bus Speed:	667 MHz
  Boot ROM Version:	IM51.0090.B08
  SMC Version (system):	1.8f2
  Serial Number (system):	QP72415BX1W
  Hardware UUID:	00000000-0000-1000-8000-0019E33B1870


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## DeltaMac (May 4, 2012)

The video chip is a permanent part of the logic board. If that chip has failed, you have to replace the logic board.
Test the chip first by connecting a video adapter cable to an external display. You would need a mini-DVI to VGA (or DVI) adapter for that. If the video works on an external display, then it's the LCD panel that is failing (I have replaced many LCD panels on those early iMacs)
Your iMac is NOT easy to open up for repairs.


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## hopelesswreck (May 4, 2012)

Thanks very much for the advice. I hooked up the iMac to another monitor and everything looks good. 

What would I need to do to fix the LCD?


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## blue&whiteman (May 4, 2012)

Since it's obviously not the GPU if the external screen works perfectly I would simply treat your iMac like a tower for the rest of it's life.  You could even put the iMac on the floor or to the side now since you only need access to the optical drive and connections.


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## DeltaMac (May 5, 2012)

You can't "fix" the LCD.
The problem is solved by replacing the LCD panel.

blue&whiteman solution is one choice (not one that I would pursue, but leaves your system usable without needing to open up the iMac.
And, the LCD would remain active, even with an external attached.
I would likely open the iMac, and disconnect the LCD display. 
Then again, not too practical, as some situations would find your iMac trying to use ONLY the internal, which would not be viewable. An example of that would be reinstalling OS X.


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## blue&whiteman (May 7, 2012)

+1 on opening it up just to disconnect the internal screen.  It will both lower heat inside the iMac and put less strain on the power supply.  The 17" LCD would use approx. 50-65 watts.


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## DeltaMac (May 7, 2012)

But - 
probably not a good solution, because the internal display would remain the default for the system, even if the LCD panel is not powered on.


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## blue&whiteman (May 7, 2012)

DeltaMac said:


> But -
> probably not a good solution, because the internal display would remain the default for the system, even if the LCD panel is not powered on.



Regardless of that the internal is almost dead.  Better to just cut the connection to it to save the heat and power.  For things like installing the OS just access the iMac drive in Target Disk mode from another Mac and install that way.


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## DeltaMac (May 7, 2012)

Not everyone has access to a second Mac that will also boot the same OS X version.
I'm just saying that disconnecting the internal display is OK as a temporary measure, but not practical for the long term - plus the challenge of opening up the older intel iMac models is "interesting", especially the first time.


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## blue&whiteman (May 7, 2012)

It was your idea in the first place but it is a good one IMO.  I guess you could get through an install with half a screen but maybe not a novice.

I know from experience (I'm an ACMT) that the white G5 and early Intel iMacs are much easier to get into than the newer aluminum/glass iMacs.  A careful novice can easily get into one but with the aluminum models you can easily disconnect and damage 3 cables if not careful.  The white models are almost as easy to open as a tower.  Simply loosen the bottom 3 screws and open the back.  Only thing to be careful of is the one cable for the iSight.


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## DeltaMac (May 7, 2012)

(sorry, more caustic than I was hoping)
There's more than one ACMT here (now who could that be?)
I hope that you remember when next you work on an early intel iMac that none open from the back...!


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## blue&whiteman (May 7, 2012)

You're right!  My mistake.  I was only thinking of the G5 iMacs which are extremely easy to open.  I still say the white Intel are easier to open vs the aluminum.

I wasn't trying to throw experience around at all.  I have more pride in my beloved G4 towers than I ever will in myself.


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