iMac 2010 wont go past startup, strange blinking!

[realpancake]

Hi,

So I tried to do a little research before I posted anywhere but I've not found many with the same issue as me.

I recently was having problems with the screen going black / off after working for a while. I was working with it on the lowest brightness as any higher would just make the screen cut out and I'd have to restart.

I had attributed all of the above overheating and installed a program to manually control the fans which really helped out.

I left my iMac off for a few days whilst I was away and upon return it wont boot up.

I hear the chime and see the logo followed by loading bar but around the around half way to 3/4 full the screen goes white for a few seconds and then turns off & randomly blinks on.

When it blinks I can see the loading bar where it got up to and a spinning wheel (not the multi colored one but white with lines)

I have reset the PRAM and SMC and can see my HD and SSD to boot from when I boot with option. I'm on 10.11.1 I think.

Any help or information would be great!

 

[realpancake]

Could this be a graphics card issue?

 

[Willo34]

My guess is that either your drive is broken or the software is faulty.....

 

[realpancake]

My guess is that either your drive is broken or the software is faulty.....

Harddrive?

It is showing 2 different drives on my screen when I boot with option, Macintosh HD & Recovery partition. If I boot from this second option am I jeopardizing any of my data?
[doublepost=1471342321][/doublepost]In a bizarre turn of events I went thru resetting the PRAM a few times, I have now been shown a welcome screen with an option to choose the language. I'm not sure what is going on and am slightly worried about wiping any data on my drives... should I proceed?

 

[Willo34]

No, don't proceed. You need to go to a repairstore and have it looked at mate, good luck (yes, harddrive)

 

[realpancake]

No, don't proceed. You need to go to a repairstore and have it looked at mate, good luck (yes, harddrive)

Is this not just recovery mode?

 

[Willo34]

Don't think so, wouldn't take the risk.

 

[IngerMan]

Is this not just recovery mode?

Can you get to Disk Utilitiy and try repair hard drive?

 

[realpancake]

Can you get to Disk Utilitiy and try repair hard drive?

I tried to boot off the recovery partition and this also resulted in the screen turning white after about 50% of loading, turning black and flashing back on & off with the apple logo the loading bar half full and the spokes loading logo in-between the two

 

[realpancake]

I managed to get into Disk Utility and repaired my drives without any trouble however the issue still remains.

So far I have Reset PRAM & SMC, repaired the HDs, tried to boot from recovery partition and checked for beeps without RAM.

Should I re-install the OS from the Disk Utility page next?

I have TM back-ups on an external but I'm not convinced that the HD's are faulty, Could it be the GPU?

 

[realpancake]

I should probably add that whilst repairing the drive I noticed that it was fairly full - could this be an issue and if so how would I go about making some room?

 

[AppleNewton]

The Recovery HD has no bearing on this, and highly doubt its your hard drive. sounds like either a graphics card, LCD going out, or bad inverter cable. you may need one or all of those repaired.

 

[realpancake]

The Recovery HD has no bearing on this, and highly doubt its your hard drive. sounds like either a graphics card, LCD going out, or bad inverter cable. you may need one or all of those repaired.

If it was the LCD dying I would see it loading and finally arrive on the user login page whilst it was flicking on and off no?

I am currently sitting idle on the welcome / select a language page whilst I figure out my next step. I will look up the inverter cable now and possibly get my suction cups out again (yey)

Replacement GPUs look incredibly expensive!?

 

[AppleNewton]

Not sure with the LCD, it could be getting enough power to show up and then exhibit those issues. I've see the LCD cables cause a lot of problems too, they're taped to the back of the display and it could be the heat of it causing them to malfunctioning. Its been a while since I've worked on pre-2012 iMacs.

Yeah GPUs are no joke price wise, you may be able to find a as-is for Parts iMac on eBay that you could scrap from for the same price or less of the GPU.

the only other thing I could suggest is trying to boot from an external drive and try to isolate the drives, but if its occurring on Recovery and Mac OS...seems to be something else

best of luck, let us know how it turns out.

 

[realpancake]

A little update. I've tried all of the following with no change.

(I have one last stupid idea left...)

•PRAM reset (Cmd+Opt+P+R),
•SMC reset (unplugged power for a while & held down power button for 5 - 10 seconds),
•Repaired the disks via Disk Utility (Option) but still wouldn't boot from HD or Recovery,
•Tried Booting in Safe Mode (Shift) this loaded further to maybe 85% and hung on the loading screen with Spokes frozen before flashing on & off again.
•Removed RAM and powered up where I hear the beeps repeating,
•Checked diagnostic LEDs - all 4 seem to appear although it's extremely hard to see them through those little holes!
•Tried to run an Apple Hardware Test (Option + D) over WiFi but I received the error "Apple Hardware Test Does Not Support This Machine" - I couldn't perform an EFI Firmware update as I don't have the disks,
•Recovered my data via Target Disk mode (T) to my laptop via Firewire. I also freed up a bit of space on the startup disk as I only had ~5GB available

So as for my stupid idea..
Removing the GPU and attempting to reball either in an oven (~10 mins @2-300 degrees C) or with a heat gun / soldering iron.

Thoughts?

 

[grahamperrin]

Apple Hardware Test (Option + D) over WiFi

Instead, use the disc that came with the iMac.

 

[realpancake]

Instead, use the disc that came with the iMac.

Sadly, as I mentioned, I don't have the discs!

 

[grahamperrin]

Sorry! I used my browser to seek the word disc (commonly used for optical discs), so it missed this:

I don't have the disks,

Still, I should have looked more closely.

If you're not too far from an Apple Authorised Service Provider (AASP) you can plead for a run of Apple Service Toolkit (AST). The provider may charge a reasonable fee for the service, which involves Netboot, so plead gently

If a problem with a drive is suspected, then have someone burn to disc a copy of Ultimate Boot CD (UBCD), which includes powerful utilities such as HDAT2.

Note that a Disk Utility repair of an HFS Plus volume may result in a disk that is apparently OK when truly, serious problems remain undiagnosed.

 

[wolf1734]

Hello
I also have a problem of videos on an iMac 27 " of 2010 the processor is I7 it works on Windows 10 but not on El capitan. needs ' he(it) that I change the graphics board and the which I can put above?
Can you one put a graphics board of an iMac of 2009 tops or located I to oblige to put back(to hand) the same. Thank you very much for your answer.
Cordially