iMac boots into black-screen, but works after about 10 tries.

[Ande333]

Hi!

My Imac mid 2011 - 27 inch won't boot. I hear a chime, the fans and harddrives go but the screen is black.. Though after force-rebooting it around 10 times it eventually gives in and boots. Once it boots everything works perfectly.

As my work station this is of course not something I can't afford to live with if it one day doesn't boot at all.

What I have tried:

- Boot with options, single user mode, command+v, disk eject ectect and it does nothing. Just black screen. (until it eventually gives in and boots after about 10 tries)

- SMC and PRAM reset, No difference.

- Updated to El Capitain and did the clean disk 7 times. Did no difference.

- first 3 leds are lit on the logic board when trying to boot. 4th gives no indication.

- Tried to replace the power supply module to a fresh one, did no difference.

- Tried to remove the RAM to see if it could be the motherboard. Had the result of the 2 first leds lit along with a steady array of beeps with an interval of a few seconds.

- Apple hardware test (advanced setting) and disk utility check says everything is normal.

- connected a second screen to see if anything was displayed on it when trying to boot. 4 times out of 5 it would stay disconnected. 1 time out of 5 it gave a loading screen that shifted in brightness levels, loaded halfways and just died into a grey screen.

- Anti virus shows nothing.

When it does boot:

- It sometimes asks me to select a language to install el capitain once it boots (although it's already installed), I just press restart and it reboots into normal.

- Once it's booted, I can put it into sleep, turn it of and even remove the power cable for an hour or two and it will reboot perfectly. It's only when It's been of power for several hours that it starts to give the problem.

Only problem I noticed before the problem started occurring was that my internet browser would sometimes crash. Not sure if it has anything to do with it.

I have no idea what it can be. I have no apple-care and I don't want to spend the money to turn it in to them at this point. Anyone any smarter then me on this? Please help!

 

[honestone]

We need some information to try and help you.

1. What exact version of El Capitan are you now using? And, what OS did you upgrade from?

2. Are you making any backups to an external device?

3. Have you ever done any disk cleanup/maintenance/repairs?

4. How much free space do you have on your internal hard drive?

5. Do you have either MacKeeper or CleanMyMac on your machine? If you do, get rid of them IMMEDIATELY, as they do more harm than good?

6. You mentioned "Anti virus shows nothing". What anti virus software are you using? Some can cause issues and/or slow downs.

From the "sound" of your issues, there could be some problems related to Permissions. There is an excellent freeware program called Onyx that can help (also help with some other issues), but we need to know about backups first.

Also, when you say "did the clean disk 7 times.", how exactly did you do that?

 

[oldscribe]

Hi,

My Imac mid 2011 - 27 inch won't boot. I hear a chime, the fans and harddrives go but the screen is black..

Check this out,

http://9to5mac.com/2013/08/16/apple-opens-graphics-card-replacement-program-for-some-mid-2011-imacs/

You may qualify.

 

[honestone]

Did not know that oldscribe. Yes, the op needs to check that out. But, he needs to also follow through on backups, disk maintenance, nefarious software removal, etc.

 

[Ande333]

We need some information to try and help you.

1. What exact version of El Capitan are you now using? And, what OS did you upgrade from?

2. Are you making any backups to an external device?

3. Have you ever done any disk cleanup/maintenance/repairs?

4. How much free space do you have on your internal hard drive?

5. Do you have either MacKeeper or CleanMyMac on your machine? If you do, get rid of them IMMEDIATELY, as they do more harm than good?

6. You mentioned "Anti virus shows nothing". What anti virus software are you using? Some can cause issues and/or slow downs.

From the "sound" of your issues, there could be some problems related to Permissions. There is an excellent freeware program called Onyx that can help (also help with some other issues), but we need to know about backups first.

Also, when you say "did the clean disk 7 times.", how exactly did you do that?

----------

Great!

1) 10.11.5 from 10.8.5

2) No, not with time-machine or Icloud or anything, have never done. I did a backup of all my important data on an external hard drive as soon as the problem started.

3) I've done cleaning of unused space with the disk utility to make it run faster. 2-3 times over the last 2 years I think.

4) Right now 766 gigabytes out of 1 TB. Before the update and reset I had some 160 gigabytes of free space.

5) No but I did have a program called "Disk Inventory X" to keep an eye over disk usage.

6) I had Sophos on it. Now Avira.

The disk utility has a security option when deleting where they overwrite the free space 7 times. I used that one when updating to El Capitain to make sure every potential problem from the HDD would be gone.

Should I try to install and run Onyx?

Regarding the graphic card replacement I'm afraid I won't qualify as I've had my computer for some 5 years.

Thank you, I really appreciate it.

 

[honestone]

OK, thanks for all that.

Regarding "I did a backup of all my important data on an external hard drive as soon as the problem started", did you just "drag and drop" stuff from your internal drive to your external one? While "OK", to do any kind of full blown recovery, it is best to have a "program-based" backup, that is, using something like Time Machine, SuperDuper!, or Carbon Copy Cloner.

Using Disk Inventory was fine, but using Avast can slow down your machine. Not sure if it causes any other issues, as I don't use (nor need) an anti-virus program.

You could try and install both Onyx and Malwarebytes Anti-Malware and see if it helps. The distinct possibility, though, of the graphics card needing replacement is definitely a concern. You can get those excellent free programs from here:

Onyx: http://www.titanium.free.fr/onyx.html - Make sure to get the first version on that list, V 3.1.7, as you are using El Capitan.

Malwarebytes: https://www.malwarebytes.org/antimalware/

If neither of them help resolve the issues, and given that you do not have a more advanced Disk maintenance/repair program like either TechTool Pro or Disk Warrior, then as a last resort, you will need to Erase and Format your internal drive. To do that, you'll need access to another Mac. And, you'll need to have the file "Install OS X El Capitan".