Complete meltdown, iMac don't know what to do

[torminaz]

Hello all

I am having some difficulties right now with some apple products and I am running out of options. I have been building and repairing PC computers for years, I don't do it as a job but as a hobby. I am no where near an expert or anything. A coworker who noticed I know computers a bit asked me recently if I could fix his iMac 21.5 / 3.06 / 2x2gb / 500gb ----- (So the MC508CA).

So the iMac has this screen issue where it powers up and gets to a kind of weird multicolor screen, then it turns gray and it turns blue. I did some reading online and apparently this model had some factory hardware screen problems with some connectors/transistors which does that to the screen...They were suggesting changing some physical stuff inside on the mother board.

I did not feel like opening it since it seems pretty complicated, so I just ordered a cable online that would take the iMac screen image and put it on another screen. So his iMac would become like a tower computer with another screen.

Problem is... It copies the buggy image =( I was sure it would project a non buggy image on the other screen. So I don't know what to do anymore. It seems the hardware is broken and I can't project the image '' correctly '' on another screen...

Anyone have any idea what to do with this?

 

[redheeler]

Looks to me like a GPU fault, which would explain the strange patterns and why the external monitor is affected as well. Would still try a fresh install of the operating system, just to rule out anything software-related.

 

[torminaz]

Even if I wanted to try a reinstall how would I do that if the screen is always this way?

 

[DeltaMac]

If the issue appears on the internal screen only, then it would be the LCD panel, or the LVDS cable connecting the display to the logic board.
As you have identical issues on an external display - then the common point is the video card. On your 2010 iMac, Apple calls it a GPU card. Takes some time to replace (and you have to find a replacement to actually do that, eh?) and a challenging repair, but not quite as involved as the same task on the newer, thin iMacs. Here's a repair guide for you to look at: https://www.ifixit.com/Guide/iMac+Intel+21.5-Inch+EMC+2389+GPU+Card+Replacement/6272

Apple's original part number can be used to find a replacement card, if you want to try that.
Part number is either 661-5539 for the stock 256MB vid card, or 661-5546 for the upgrade 512MB vid card

 

[redheeler]

Even if I wanted to try a reinstall how would I do that if the screen is always this way?

If you try and boot from a Recovery partition or DVD and it still does that, you have a strong indicator of a hardware (GPU) issue. Something else you should try first if you haven't already is an NVRAM reset.

 

[DeltaMac]

You CAN reinstall OS X, even if you can't see the screen, if you have another Mac with Firewire connected between the two Macs, using Target boot mode.

2010 iMac came with Snow Leopard, and MAY still have that installed, which would not have a recovery system installed (and no internet recovery available either, if the system was never updated. That's always a possibility. )

 

[torminaz]

If the issue appears on the internal screen only, then it would be the LCD panel, or the LVDS cable connecting the display to the logic board.
As you have identical issues on an external display - then the common point is the video card. On your 2010 iMac, Apple calls it a GPU card. Takes some time to replace (and you have to find a replacement to actually do that, eh?) and a challenging repair, but not quite as involved as the same task on the newer, thin iMacs. Here's a repair guide for you to look at: https://www.ifixit.com/Guide/iMac+Intel+21.5-Inch+EMC+2389+GPU+Card+Replacement/6272

Apple's original part number can be used to find a replacement card, if you want to try that.
Part number is either 661-5539 for the stock 256MB vid card, or 661-5546 for the upgrade 512MB vid card

Thanks much, that seems to be the solution but the part is very expansive (150 ish to 280 ish depending on the website) and like most people he's not gonna be willing to pay for that part, I am sure. Gonna have to give him back his stuff and charge him for not fixing his problem lul.

 

[verdejt]

Thanks much, that seems to be the solution but the part is very expansive (150 ish to 280 ish depending on the website) and like most people he's not gonna be willing to pay for that part, I am sure. Gonna have to give him back his stuff and charge him for not fixing his problem lul.

Check on eBay. I've been seeing video cards cheaper than from places like dv warehouse.

 

[joema2]

...It seems the hardware is broken and I can't project the image '' correctly '' on another screen...Anyone have any idea what to do with this?...

This is apparently a 2010 iMac 21.5. It is almost certainly an internal hardware problem. However you can try running Apple Hardware Test to get more detailed information: https://support.apple.com/en-us/HT201257

 

[tyche]

The 3 big reasons for these failures are: graphics card, screen panel, LCD inverter board.