imac 2011 - not booting - apple logo then white screen

[amt976]

Hi All,
apple logo and then white screen. Replaced 3,5 HD (which seemed dead) with clean 2.5 SSD and booting from USB with High Sierra.
Still, problem persist. Apple logo and then stuck on a white screen.
All devices unplugged, only power cable and USB stick.
any help?
imac 2011 21,5"

 

[Fishrrman]

Bad GPU...?

 

[vkd]

You could hold "command+V" whilst booting to get a verbose black & white text-based boot and try and see what it fails on.

 

[koden]

I have same problem.. imac 2009.
Not used for several years.
Not mine so don't know what OS it have.
Could not start up in any OS
Replaced HDD with SSD
installed capitain.
Install runs fine and counts down to about 2 min.
Black screen and back white screen.... and there it stays.

original disk back.
Tried to install on that.
Same issue

Then i read something about clock setting could be wrong.
Boot on el capitain disc and run terminal.
DATE tells me it,s today but PST time.

I then set time to DATE -u 0203180619
2019 because I have read about certificate problems from nov. 2019
When setting time terminal answer back with UTC time and the time i Set.
Run DATE again and now i'm on PST time again ?????

I have just tried so many things, and always endning in white screen.
NVRAM reset is done

I have seen lots of GPU errors with stribes on the screen...but could this be GPU when no signs of that vertical stribes?

Will try to make yosemite USB boot key and try that..

Any ideas?

 

[amt976]

I have same problem.. imac 2009.
Not used for several years.
Not mine so don't know what OS it have.
Could not start up in any OS
Replaced HDD with SSD
installed capitain.
Install runs fine and counts down to about 2 min.
Black screen and back white screen.... and there it stays.

original disk back.
Tried to install on that.
Same issue

Then i read something about clock setting could be wrong.
Boot on el capitain disc and run terminal.
DATE tells me it,s today but PST time.

I then set time to DATE -u 0203180619
2019 because I have read about certificate problems from nov. 2019
When setting time terminal answer back with UTC time and the time i Set.
Run DATE again and now i'm on PST time again ?????

I have just tried so many things, and always endning in white screen.
NVRAM reset is done

I have seen lots of GPU errors with stribes on the screen...but could this be GPU when no signs of that vertical stribes?

Will try to make yosemite USB boot key and try that..

Any ideas?

tks. I can add I've tried everything: boot from USB with High Sierra, internet recovery, SATA HD and SSD replacement, hardware test (no faults detected), cmd-optn-P-R reboot, etc.
I cannot even access safe mode, when I hold shift it starts loading safe mode but blinks back to white screen..

 

[koden]

I gave up... installed SSD disk.
Deleted all MAC related stuff.
Installed win 10.

Only one problem.... no driver for graphic card AMD 4800
So when running win update some graphic driver is installed and screen goes black.
in GPEDIT I have disabled update for graphic card and just running windows standard driver.

It works fine but off course I miss settings for graphic..
But seems not to exist...the win 10 driver for AMD 4000 serie.