White screen on Imac 2011

[Alent]

Agreed.

There's something wrong with the install as it is at present. Only way round is to try again following Apple guidance.

So shall i reformat and erase the ssd and try and download high sierra again?

 

[UtterDisbelief]

If you have anymore questions about it please ask i’ll answer to best of my ability Thanks for the help though

So, did you create a new USB installer stick with the Terminal command: createinstallmedia?

If so were you able to use that to boot the iMac and begin installing?

If not, it's a firmware problem, but if you can then you should point the installer at your SSD and go from there ...

No need to re-download if you already have it. If not, then yes, download but keep it somewhere safe. Apple tells you the createinstall media command but if you check our High Sierra beta version install guide it is given there too.

 

[trs96]

I found this on Mac Rumors forum. Appears that a white screen can be a 6970M related problem.

Bit of a back story. I bought my Mid-2011 iMac 27" from Apple in 2012. Everything was great until 2015 when it started having the infamous graphics issue (symptoms included artifacts on screen, vertical bars, or full on white screen).

Apple did recognize this as a "known issue" in my Mac and replaced the graphics card (AMD Radeon HD 6970M 1GB) free of charge even though the machine was out of warranty. Great!

Now, 4 years later the same issue is back. However at this point, Apple says the machine is "vintage" (5+ years by definition from Apple) and they no longer stock parts for it, so even if I wanted to pay for a repair I'm out of luck. I did have a tech look at it at an Apple store, and their diagnostics didn't show any issues (apart from it having non-Apple RAM). The tech told me that:

- Given the original graphics card was replaced, this issue would not be strictly the same as the original one. Their hardware diagnostics are specifically designed to look for the original "known issue" with these graphics cards, so just because it's not detecting a graphics issue doesn't mean there isn't one.

- Although unlikely, the non-Apple RAM could also be the culprit.

- Assuming it is a video card issue my only option would be a third-party repair or replacement. He did mention that there may have been third party manufacturers making cards that work for the iMac, so there could be a chance of finding a new third-party part.

 

[Alent]

I found this on Mac Rumors forum. Appears that a white screen can be a 6970M related problem.

I see, so shall i look into buying a new graphics card then? or what did you do after it came back again

 

[Alent]

So, did you create a new USB installer stick with the Terminal command: createinstallmedia?

If so were you able to use that to boot the iMac and begin installing?

If not, it's a firmware problem, but if you can then you should point the installer at your SSD and go from there ...

No need to re-download if you already have it. If not, then yes, download but keep it somewhere safe. Apple tells you the createinstall media command but if you check our High Sierra beta version install guide it is given there too.

Yes i think its a firmware problem then as it didn’t work with the bootable usb before but i will definitely try it again

 

[trs96]

what did you do after it came back again

That quote from Mac rumors was not me. I've never owned one of those model iMacs.

 

[Alent]

That quote from Mac rumors was not me. I've never owned one of those model iMacs.

Oh i see sorry

 

[trs96]

I see, so shall i look into buying a new graphics card then?

To go that route will take a lot of time money and research to have success. I really don't think that it's worth it. Doesn't hurt to try but there are better solutions such as building your own hackintosh. I've heard there's a good forum somewhere online for that.

 

[UtterDisbelief]

Yes i think its a firmware problem then as it didn’t work with the bootable usb before but i will definitely try it again

To quote another Internet resource for repairing Firmware on an iMac:

"Press the power button, and as soon as you power up the laptop, iMac, hold down Command-Option-P-R. Keep holding down those keys for about 20 seconds."

 

[Alent]

To go that route will take a lot of time money and research to have success. I really don't think that it's worth it. Doesn't hurt to try but there are better solutions such as building your own hackintosh. I've heard there's a good forum somewhere online for that.

Can you forward me to them becaus ei myself have never heard of it