iMac white screen with Stripes

[cozmacray]

iMac early 2008 A1224 2210 20"

On boot up white screen with vertical colored stripes
image of screen below

System bongs so POST is passed
I used firewire target disk mode to get to HDD

What dianostics can I run?
What part is broken?

I have it apart and checked all cables and connections
Diagnostic LEDs are all on

Tnx for any help

 

[honestone]

First of all, what OS are you using?

Secondly, when you say "System bongs so POST is passed", does that mean you then get the Apple symbol, and the spinning "circle"?

Third, here are the results of a google search of "iMac White Screen with Stripes":

https://www.google.com/search?q=iMa...la:en-US:official&client=firefox-a&channel=sb

I read a couple of them, but I don't know which ones apply to your Mac model? Also, again it is important to know what OS you are running. Also, for one of those links, the user had to get a new graphics card.

If you have Tech Tool Pro on the machine that you are "attaching" the iMac to in Target Disk Mode, that program does have a feature for checking the Video Memory. Not sure if that would help or is applicable to your issue, but it could be worth a try.

 

[cozmacray]

OS X 10.6.X on internal HDD
No apple or spinning circle --- just white screen with stripes

Do different Max OS X versions treat video displays different?

Replaced the video card with a known good card with same screen result.

So Tech tool pro can diagnose a firewire attached mac?
How --- it's just using mac firewire interface to internal HDD?

Mac POST
At power on, the firmware runs the Power-On Self Test (POST), which tests the processors, system memory, and network (Wi-Fi, Ethernet) and peripheral (USB, FireWire, Bluetooth) interfaces. If your hardware passes the POST, the startup chime (Bong) is sounded.

My iMac does not beep and declare any POST failed.

I have done plenty of Google searchs with no help?

Tnx

 

[honestone]

Regarding different OS X versions treating video displays differently, this link contains various "types" of updates for iMacs:

http://support.apple.com/kb/HT1599

Note that there is one for your iMac model that states:

"This update is for specific iMac computers with an ATI Radeon HD 2600 Pro or ATI Radeon HD 2400 XT graphics card installed, running Mac OS X 10.5.2 or later."

Not sure if that will "fix" your problem.

As for Tech Tool Pro and your iMac attached in Target Disk Mode, yes, it can "analyze" the hard drive in your iMac. Basically, your iMac will be seen on the "active" machine as a Firewire Drive. However, I am unsure about Tech Tool Pro's ability to check out the Video Memory on the iMac. Theoretically, it "should" be possible, but I have never tried it.

What type of video card did you recently put in the iMac? If it's not an ATI Radeon HD Pro or ATI Radeon HD 2400 XT, the link I provided above regarding the update would not be applicable. If that is the case (especially with a known, good card), it could be something in the system software (or maybe another piece of software).

When did this behavior start happening? Do you have a backup prior to this problem happening?

 

[Kaveman]

This is a hardware problem, you'll need to take it to an AppleCare Service Centre near you.

 

[honestone]

This is a hardware problem, you'll need to take it to an AppleCare Service Centre near you.

But, at least try the software suggestions I gave above (along with some of the information from the links).

 

[cozmacray]

I used Tech tool 7 with this iMac in firewire Target disk mode
I can do HDD tests but NOT system tests
and
I cannot install the iMac EFI LCD update because it sez
"this mac (my Mac9,1 macbook) doesn't need it"
and no way to select it to be installed on the iMac system
Unless there is a way to inject it into iMac HDD.

So only a AppleCare service center can do this?
They have special hardware / software diagnostics to find what part is bad?
??? Only a Mercedes dealer can diagnose / fix a Mercedes?
Un American

I replaces the video card --- I don't think there is a more difficult service.
Just tell me -- bad LCD , bad video cable , bad left hand raminfratzer
I'll get one and replace it and make it work!

I have been fixing Apples since Apple II
put a HDD in Mac 128
Replaced components on apple boards

Is there a file on iMac that I can look at to find exact OS on that system?

Thanks

 

[honestone]

I truly understand your frustration! I also have "dived" inside quite a few Apple machines myself, but it looks like this is an issue that can only be solved with the right diagnostic equipment.

 

[cozmacray]

Have external monitor hooked up via mini dvi to VGA adaptor.

External screen shows boot splash screen post start up.

Main iMac screen still withe with vertical stripes

Command F2 won't make external monitor main or mirror screen (or any other keyboard command)



System is operating fine as shown by "voice ON" and it speaking all the screen stuff?



Any other way to make external monitor main display so I can work with system?



Tnx

 

[cozmacray]

Mac A1224 20" 2008

Bad LCD --(you wouldn't think a LCD would fail this way)
External monitor working

Running Yosemite Newest OS X 10.10

---I got main window over to External monitor following Voice under 10.5.8
then upgraded to 10.6 then to 10.10
Now Command F1 to mirror is required on each startup

it might be cheaper to just put a nice 24" monitor in front of the iMac
instead of $140 for replacement LCD?

 

[cozmacray]

No more stripes

They said I must take the iMac to an Authorized Apple Service Canter!!!

$100 LCD fixed it

Don't need NO stinkin Authorized Apple Service Canter!!!