Troubleshoot Display Black boot from DVD
1. Wife reported display with abnormal characters, and eventually going black
2. Apple Store Genius diagnosis as GPU Assembly failure
3. Purchased refurbished GPU Assembly from DV warehouse, tested by DV ok, 90 day warranty
4. Installed refurbished GPU
5. Power-on after installation.
6. 1st attempt to load Mac OS X from DVD to internal hard drive Disk (replaced internal hard drive since we had the computer completely opened), installation proceeded normally, then display goes black, computer appears to be still powered on.
7. Next attempt, display goes black within a few minutes.
8. Went to Apple store, recommendation to use an external monitor
9. Installed external monitor
10. Powered on, using external monitor, booting from install disk
11. Apple chime, dialog windows prompts to install OS, everything proceeding normally.
12. Apple desktop display showing on internal monitor and external monitor
13. Mac OS X installation progress bar is displayed on the internal monitor, gets down to 28 min.
14. External monitor displays just the desktop background
15. Internal monitor goes black.
16. External monitor goes black.
17. External monitor sync goes from green to amber
So, what should I focus on next to isolate the problem?
Thanks
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4 Comments
OK, I'm going to send the refurb'd GPU back to vendor for a replacement. We'll see how long this will take. thx.
by rgpphelps
Round 2.
Installed second GPU assembly from vendor. Probably a refurbished unit. Results are the same as seen in the first refurbished unit from the same vendor. I had moved the original internal hard drive to an external enclosure since having to change the GPU opened up access to the hard drive. I had installed a new Seagate drive in the internal drive location. I then connected the original hard drive installed, now moved to an external firewire 800 enclosure and tried to boot from the external drive. I used a startup disk power-on option to select the external drive.The system just went to a white internal screen display and never booted. The display went white for a long time, never got a signal to display an image, but, it never went black. Why does it go black when installing from DVD, but not when trying to boot from external drive? I'm going to reset the SMT to see if that has any effect. Another suggestion was to re-install the original internal hard drive, I'll try that after the SMT reset .
by rgpphelps
Round 3
Getting desperate.
Put the original hard drive back in. Nothing was originally wrong with it, just wanted to upgrade capacity. So, the only difference now is the iMac has the second refurbished GPU assembly installed. Now, I just have enough time to log in to an account and the internal display goes black. When I was booting from an install DVD at least the display would be getting a signal for 17 - 20 minutes.
by rgpphelps
Round 4
Booting in Safe mode, the display is more stable and does not go to black as frequently. I need to repeat this on multiple starts to confirm. But, now I've noticed another problem, since I had the computer opened, I decided to change the PRAM battery. But I screwed up and broke the bottom flange that hold the battery in place. I put electrical tape on it to try and hold it in place, but it's not a tight fit and the battery appears loose. So now I've introduced another variable. I'm going to try and figure out how to hold the battery firmly in place.
by rgpphelps