iMac 2007 Black Screen

[wagszilla]

Hi all,

My late 2009 era 27'' iMac has been acting up as of late. It started yesterday and continued today.

Running OS X El Capitan, whatever the highest spec on my model was, & RAM upgrade.

The display will basically shut off but the computer is still on, as I can hear the processor running.

I thought it might be a temperature issue and tried to download iStat Pro but it wouldn't work and now I'm back at black screen so I can't try further.

No issues before this.

I will continue to google around but wanted to see if anyone had any thoughts.

EDIT: To clarify... boots fine, just goes black after awhile at random.

 

[iemcj]

Get smcfancontrol if istat won't work for ya. I doubt it's heat though, screen wouldn't go all black. When it goes black, does it stay black and never come back on? If you do a hard restart (power button) does it come back on right away?

 

[wagszilla]

Right now the display is working again after resetting the computer (it was on with a black screen for roughly 2 hours while I went out to run errands and backup files).

Previously it came back on after reset but only for about 2-3 minutes before going to the black screen again.

I'm currently at about the 15 minute mark.

When it went black I was doing the following:
- Using the Photos app editing photos
- Watching videos on YouTube

Anyway, I will be taking it into the Apple store soon enough.

 

[wagszilla]

The issue subsided by-and-large since posting in September.

That said, it has returned with a vengeance. The Apple Store team ran a diagnostic and were unhelpful. Didn't tell me anything that I didn't know. I bumped up my fan speed to 1200rpm for ODD, HDD, and CPU just for laughs.

The temperatures seem fine but attaching here for reference.

I swapped out the RAM I bought from OWC just to see if that was the issue.

I'm left to believe it's Graphics Card related.

 

[texrb]

Wagzilla,

I have a mid-2010 27" iMac i7 2.93 with the ATI 5750 1GB video card. I was experiencing the same issues with the screen going black, but the computer staying on. This began after I upgraded to the latest version of Yosemite just before El Capitan was released. I read several forums and tried installing smcfancontrol - which did seem to resolve the issue for about 3 weeks, but the problem returned. My extended warranty had long since expired, so I took it to the Apple Store, to run the hardware test since it wouldn't run for me at home.

Apple ran the hardware test & all checked out ok, so they asked if they could keep it for a couple days to see if they could duplicate the problem (it would happen intermittently). I left it there with instructions to call me if they had to replace some hardware. After 4 days, they called & said they had re-imaged the HDD with a new install of El Capitan, since the problem did happen but hardware tested ok. We both thought the problem was a corrupted system file after the prior upgrade to Yosemite.

This seemed to have resolved my issue. I was able to restore all my files & settings from time machine & El Capitan still remained. It's been a month with no issues. I still have smcfancontrol installed & the system runs at 40C or lower.

There was no charge for them to do this since it was a software issue. I was certain I had a bad video card or some other hardware related issue, but I do believe it was a corrupt file because this issue started after upgrading the OS. When I bought this computer new, it had Snow Leopard & I had upgraded several times to Mountain Lion, then Mavericks & Yosemite & I believe, like any computer, continuing to upgrade on top of older OS systems does run the risk of a file corruption.

I was hesitant to upgrade to El Capitan because of the issues others had posted, but I'm happy with it. The computer doesn't boot to the desktop any faster, but once the desktop loads, it is much faster to launch my programs.