Late 2009 graphic problem

[mogens]

My late 2009 27" i7 just started up with pink and green vertical stribes.
I can't get it to boot to the desktop, -it stops at the apple logo. I can however boot from the hardware test DVD and run the tests and it reports no problems (still with stripes on the display). I use a DIY fusion drive I installed about a year ago. could it be a bad display connection? Also tried to boot from an external disk with the same result :-( (the imac freezes at the apple logo)
Any suggestions?

 

[Twimfy]

My late 2009 27" i7 just started up with pink and green vertical stribes.
I can't get it to boot to the desktop, -it stops at the apple logo. I can however boot from the hardware test DVD and run the tests and it reports no problems (still with stripes on the display). I use a DIY fusion drive I installed about a year ago. could it be a bad display connection? Also tried to boot from an external disk with the same result :-( (the imac freezes at the apple logo)
Any suggestions?

Sounds like the GPU is on the way out. Wouldn't hurt to open it up and check the connections just to be sure but I'd be prepared for the worst.

Can you boot in safe mode? Usually when a GPU has cooked you can get in with Safe mode as it only loads basic drivers/kexts (as does AHT).

 

[mogens]

Yes I'm afraid it's toast
I removed the display panel and vacuum cleaned the inside (not much dust to be seen). If I start after the iMac when it's cold, it runs perfect for about half an hour, but then it freezes with pink dots on the screen.
If i boot in safe mode it freezes if it's hot, else it boots normal.
I can boot in target mode too (when it's cold).
What a shame I love this iMac. After I installed the SSD it's been running like a dream. It's the model with a radeon HD 4850 graphic card. Any idea what a repair would cost? I think I read somewhere that the graphic card is serviceable and not soldered to the main board. Does anybody know where I could buy this or a another compatible graphic card?
Now I'm stuck with a ****** compaq notebook and don't have the money for a new iMac...

 

[Twimfy]

Yes I'm afraid it's toast
I removed the display panel and vacuum cleaned the inside (not much dust to be seen). If I start after the iMac when it's cold, it runs perfect for about half an hour, but then it freezes with pink dots on the screen.
If i boot in safe mode it freezes if it's hot, else it boots normal.
I can boot in target mode too (when it's cold).
What a shame I love this iMac. After I installed the SSD it's been running like a dream. It's the model with a radeon HD 4850 graphic card. Any idea what a repair would cost? I think I read somewhere that the graphic card is serviceable and not soldered to the main board. Does anybody know where I could buy this or a another compatible graphic card?
Now I'm stuck with a ****** compaq notebook and don't have the money for a new iMac...

eBay is your best bet, although there's a few dedicated Mac part dealers across the net.

My estimate is that Apple would charge around £150-200 for a replacement. GPU repairs are usually expensive but it wouldn't hurt to drag it to the genius bar and see what they say, you might get lucky or it might be less than you think.

 

[SaSaSushi]

The part alone is going to run you $300 to $400 even on eBay. Apple will charge that plus labor. I would be very surprised if it was less than $500.

These guys on eBay will apparently repair the GPU and insure it for 3 months for $99.95. You just send them the GPU itself and they repair and return it to you.

It would seem to be the cheapest option.

 

[Thessman]

Yes I'm afraid it's toast
I removed the display panel and vacuum cleaned the inside (not much dust to be seen). If I start after the iMac when it's cold, it runs perfect for about half an hour, but then it freezes with pink dots on the screen.
If i boot in safe mode it freezes if it's hot, else it boots normal.
I can boot in target mode too (when it's cold).
What a shame I love this iMac. After I installed the SSD it's been running like a dream. It's the model with a radeon HD 4850 graphic card. Any idea what a repair would cost? I think I read somewhere that the graphic card is serviceable and not soldered to the main board. Does anybody know where I could buy this or a another compatible graphic card?
Now I'm stuck with a ****** compaq notebook and don't have the money for a new iMac...

You could try http://www.powerbookmedic.com/xcart1/_search.php?mode=search&q= , I have no personal experience with these guys, but you can get a quote (Send in Mac-repair).

 

[mogens]

The part alone is going to run you $300 to $400 even on eBay. Apple will charge that plus labor. I would be very surprised if it was less than $500.

These guys on eBay will apparently repair the GPU and insure it for 3 months for $99.95. You just send them the GPU itself and they repair and return it to you.

It would seem to be the cheapest option.

Thanks, Looks good. I think I'll give it a try now that I've allready tried to take the imac apart when I did the DIY fusion install.

 

[mogens]

Did a DIY reflow of the GPU. 8 min. 200 degrees in my kitchen oven. Now everything works like a charm, you have to see it to believe it
I think it's the same trick the guys on Ebay uses.

 

[SaSaSushi]

Awesome! I'm glad to hear it! I would venture a guess that you are absolutely correct about the eBay guys doing reflows too.

 

[philsurmac]

Hi there,

I've just baked it in oven and it works

What have I done :

- heat the oven at 180 degrees (celcius) for 15 mn
- Put my HD 4850 for 6 mn (3 mn on one side, 3 mn on the other one)
- the HD was in an aluminium sheet, carefully lied on a plate
- I removed everything from the GPU (papers, rubbers, thermal paste)

Now everything is working back... hope it will last

 

[RichMcM]

Is your GPU still working after a good baking? I have the same iMac/video card and its doing exactly what you described...

Hi there,

I've just baked it in oven and it works

What have I done :

- heat the oven at 180 degrees (celcius) for 15 mn
- Put my HD 4850 for 6 mn (3 mn on one side, 3 mn on the other one)
- the HD was in an aluminium sheet, carefully lied on a plate
- I removed everything from the GPU (papers, rubbers, thermal paste)

Now everything is working back... hope it will last

 

[philsurmac]

Yes, I've done it to several iMacs and they seem to all still work.
Also done it with logic board (it starts to be an habit) and I saved maybe a dozen..

Let's say that despite all the doubts on forums, 85% of the time it keeps working for a long time. And, if it breaks again, do it again, and again. I can advise you to try at least four times to decide to throw your graphic card..

 

[philsurmac]

By the eay I put 200 degrees and leave it 10 minutes, not less.. Don't read anything else on internet, it's working well like that.

 

[orange.x]

By the eay I put 200 degrees and leave it 10 minutes, not less.. Don't read anything else on internet, it's working well like that.

So, just unscrew everything, remove papers and stuff, put oven on 200 degrees and then 10min in, then directly out? Or just turn oven down and let it rest until it's cold? Then screw everything in, thermal paste and stuff and it works?

Today got the same problem. Have somebody who wants to do it for around 100 euros. But this can be done by myself, I'm not that scared of the screwing and opening, removed my dvd drive and placed an ssd in it so been there done that.

How many times did you have to do it to your own iMac for the past time? Or just once?

Love to hear