iMac 27-inch Mid 2011 backlight problem
Over the past few months, my iMac backlight has been going out at random times while I'm using it. At first, this occurred very infrequently (maybe once every couple of weeks) and now it occurs very frequently (almost every time I use the iMac). It took me a while to figure out that the iMac was not going to sleep, not hanging, and not freezing. The backlight was simply going out but otherwise the machine was functioning fine. For instance, I can "Share the Screen" from my MacBook and use the iMac while the built-in screen is black or I can hook up an external monitor and use it in place of the built in display when it decides to go out. I also learned that I could force the backlight to come on by manually putting the iMac to sleep (CTRL+Shift+Eject...then pressing space to wake it). When the iMac is "acting up", it frequently just shuts the backlight right back off in a matter of seconds after waking it from sleep. While searching for a possible solution, I tried all the suggestions I found like: reset SMC, reset NVRAM, run with brightness low, run with brightness high, run with brightness at half, turn off ambient light sensor, turned off hot corners, etc. These procedures do not change or improve the behavior. Right now, the iMac is out of warranty and I am convinced that this is a hardware problem. I believe my only practical option is to take the iMac in to Apple to have it repaired. I suspect the repair will be expensive but if it's less than say...$600, I will pay to it to make this machine reliable again. If it's more than that, I am probably going to scrap this machine and put the money towards a new one. My biggest fear is that I'll decide to pay for the repair...only to have it start occurring again once I get it back home. I've read posts were this happened to people but they were still under warranty. They returned the machine back to Apple again for additional component replacements before it was finally fixed.
My questions:
- Is there anyone out there that had this same issue that can share their experience/resolution?
- Does anyone have experience paying for repairs while out of warranty? How does Apple handle situations where you’ve paid for a repair (for example, parts and labor to replace component) and then you find out the original problem is not fixed?
- Does anyone have advice or suggestions that I haven't tried yet?
A few other notes:
- This started happening after I upgraded to Mavericks, but I think that is a coincidence. I may restore to the original OS as a last resort before taking the machine in for repair.
- My iMac does not have the video card that had the recall.
- When my iMac backlight is working, I never have the "half screen dimmer" or "line down the middle" issue that some other people experience.
Here’s my iMac's info:
Software OS X 10.9.2 (13C64)
Model Name: iMac
Model Identifier: iMac12,2
Processor Name: Intel Core i5
Processor Speed: 2.7 GHz
Number of Processors: 1
Total Number of Cores: 4
L2 Cache (per Core): 256 KB
L3 Cache: 6 MB
Memory: 4 GB
Boot ROM Version: IM121.0047.B1F
SMC Version (system): 1.72f2
Chipset Model: AMD Radeon HD 6770M
Type: GPU
Bus: PCIe
PCIe Lane Width: x16
VRAM (Total): 512 MB
Vendor: ATI (0x1002)
Device ID: 0x6740
Revision ID: 0x0000
ROM Revision: 113-C0170F-175
EFI Driver Version: 01.00.560
Displays:
iMac:
Display Type: LCD
Resolution: 2560 x 1440
Pixel Depth: 32-Bit Color (ARGB8888)
Main Display: Yes
Mirror: Off
Online: Yes
Built-In: Yes
iMac (27-inch Mid 2011), OS X Mavericks (10.9.2)
