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nissart

macrumors newbie
Jul 18, 2018
3
1
bad news for me. I just received the Alienware GTX 765m ordered on eBay, the same one as jml12286, but the iMac won't start. No chime, no beep, no fans turning on... only the Diagnostic Led #1 on. :(
When I remove the Nvidia card and try to power up the Mac 1/ without GPU 2/ with my almost dead AMD, the iMac powers up...

I don't know if the GTX 765m I bought is bricked or if there is some incompatibility...
 

highvoltage12v

macrumors 6502a
Mar 27, 2014
926
931
bad news for me. I just received the Alienware GTX 765m ordered on eBay, the same one as jml12286, but the iMac won't start. No chime, no beep, no fans turning on... only the Diagnostic Led #1 on. :(
When I remove the Nvidia card and try to power up the Mac 1/ without GPU 2/ with my almost dead AMD, the iMac powers up...

I don't know if the GTX 765m I bought is bricked or if there is some incompatibility...

This could be one of two issues, Either your 765m is dead (which I encountered) or you didn't modify the original X-clamp on the back of the card, and capacitors are shorted, I need more info. Which heatsink are you using? It could be from a 6770m or the 6970m (6970m needs modifications)

I ran into problems where the machine has standby power and pressing the power button would cause led 1 to go out, reseating the card fixed this issue.

To make things simpler never reassemble the machine. I installed the logic board (no screws), connected fans and power supply and OS drive. I would boot with an External monitor plugged in the Mini displayport closest to the Ethernet port. Once I had video then I would consider putting the panel back on/together.
 
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rpmurray

macrumors 68020
Feb 21, 2017
2,148
4,330
Back End of Beyond
highvoltage12v, will the iMac start without the built in display connected? I was thinking of doing as you say to test if the video card is working but wasn't sure if the iMAC would boot completely without the display connected.
 

highvoltage12v

macrumors 6502a
Mar 27, 2014
926
931
highvoltage12v, will the iMac start without the built in display connected? I was thinking of doing as you say to test if the video card is working but wasn't sure if the iMAC would boot completely without the display connected.
Yes the iMac will start with no display connectecd. The fans will run on high speed due to the missing thermal sensor.
 

Mr-Mur

macrumors member
Jul 4, 2018
50
25
Hi there fellow iMac'ers!

I also joined this GPU-upgrade-club and finally swapped stock 6770 to GTX 780M at my :apple: iMac 2011 mid-2011 27''.
But still no boot screen and lost brightness controll :eek:
iMac also got a newer i7-2600 against i5-2400s.
I published full report at my personal web-site (in Russian) so feel free to launch Google Translate.

Thank you!
2-CPUs-01.jpg GTX-780m-MXM.jpg GTX-780m-in-place.jpg
 

thewojtekr

macrumors newbie
Aug 1, 2018
5
0
Hey guys,
I've searched this topic in order to find the answer for my question but without success.

Someone gave me iMac 21.5" Mid 2010 version with broken GPU. There are vertical stripes on the screen. I know that the only option to get rid of this is GPU replacement. I found on the Internet the graphics card from Dell Alienware which is ATI HD4870M 1GB MXM 3.0b and I wonder if it is possible to replace the broken one with it? If no, what kind of graphics card can I get for 80-100$ that will make my iMac work as same as original (with boot screen and brightness control)?

Thanks in advance!
 
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FlorisVN

macrumors 6502a
Nov 8, 2013
979
380
Hey guys,
I've searched this topic in order to find the answer for my question but without success.

Someone gave me iMac 21.5" Mid 2010 version with broken GPU. There are vertical stripes on the screen. I know that the only option to get rid of this is GPU replacement. I found on the Internet the graphics card from Dell Alienware which is ATI HD4870M 1GB MXM 3.0b and I wonder if it is possible to replace the broken one with it? If no, what kind of graphics card can I get for 80-100$ that will make my iMac work as same as original (with boot screen and brightness control)?

Thanks in advance!

I don't think its not yet possible on any "non" offical MXM card to get brightness and bootscreen available yet..
Macvidcards is working on it, they have managed to get a EFI bootscreen on a nvidia 780m mxm card, but still some bugs are present like brightness and other problems..

We all hope these isseus will be fixed soon,..

check this topic and this one ( http://netkas.org/forum/index.php/topic,13815.0.html ) on netkas for more updates !

Besides that, maybay the HD4870m will work, but i highly reccomend going for an nvidia 6 series or higher, since these don't barely have isseus with heat and gpu defects.
Also MacOS mojave requires an metal compatible GPU, and with a metal GPU and dosdude1 patch, you will get best experience with macOS Mojave and future MacOS release possibly..

Check out this thread aswell, : https://forums.macrumors.com/threads/macos-10-14-mojave-on-unsupported-macs-thread.2121473/
 
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JessieComputes

macrumors newbie
Sep 11, 2016
27
8
Has anyone been able to repeat highvoltage12v's results of getting 4k@60Hz off of a Displayport connected to an external monitor? Mr-Mur, you also have a gtx780, -are you able to test this?
BTW, I have been experimenting with an external egpu setup with my 2011 iMac. Not very successful really, especially compared to what has been achieved here. Thunderbolt 1 just does not have enough bandwidth, and very clunky.
 

Mr-Mur

macrumors member
Jul 4, 2018
50
25
Has anyone been able to repeat highvoltage12v's results of getting 4k@60Hz off of a Displayport connected to an external monitor? Mr-Mur, you also have a gtx780, -are you able to test this?
BTW, I have been experimenting with an external egpu setup with my 2011 iMac. Not very successful really, especially compared to what has been achieved here. Thunderbolt 1 just does not have enough bandwidth, and very clunky.

Nope, unfortunately I never did connect external display to my iMac.
 

passatgt

macrumors 6502a
Jun 16, 2011
541
433
Last edited:

TVreporter

macrumors 68020
Mar 11, 2012
2,058
3,420
Near Toronto
The video card is gone in my 2011 27-inch imac. The Apple authorized repair guy said there was nothing he could do. I suggested a third party card and he didn’t want to recommend it given their limited warranty and unreliability.

Plus he said with part cost and labour I was looking at $700-$800 - he told me it wasn’t worth it.

So what do I do with an otherwise still good computer?
 

vkd

macrumors 6502a
Sep 10, 2012
984
381
The video card is gone in my 2011 27-inch imac. The Apple authorized repair guy said there was nothing he could do. I suggested a third party card and he didn’t want to recommend it given their limited warranty and unreliability.

Plus he said with part cost and labour I was looking at $700-$800 - he told me it wasn’t worth it.

So what do I do with an otherwise still good computer?

If you pay the postage I will take it off your hands.
 

passatgt

macrumors 6502a
Jun 16, 2011
541
433
Hi! Can you recommend me a cheap option to fix a 2010 21.5" iMac? I believe its the same MXM socket as 2011, so in theory the cards mentioned here should be compatible. I'm just looking for a cheap solution to make this running again, so i don't need any performance gain.

I'm currently looking at these two:
https://www.ebay.com/itm/AMD-Radeon...-Graphic-Video-Card-For-HP-8560W/191782584445
https://www.ebay.com/itm/ATI-Mobili...2-Video-VGA-Graphics-Card-Tested/153124850996

Thanks!

I purchased a HD4570 really cheap($15), so i will try it out and report back.
 

CuriousMacCow

macrumors newbie
Aug 12, 2018
10
0
GTX 780m Upgrades


5. In other observations I noticed that I lost the brightness function but this issue can be solve by installing 2rd party apps like Brightness Slider from AppStore. Also the new GPU cant detect my 2nd monitor using HDMI but it can be solve by using VGA instead.


VGA via THUNDERBOLT? No possible of HDMI?

Any news on the upgrade? Curious to see how it goes.

I have a 2011 iMac 27" with a faulty AMD gpu. What are the best upgrades for this? With the boot screen, brightness control etc.?

Thanks!
 

passatgt

macrumors 6502a
Jun 16, 2011
541
433
VGA via THUNDERBOLT? No possible of HDMI?

Any news on the upgrade? Curious to see how it goes.

I have a 2011 iMac 27" with a faulty AMD gpu. What are the best upgrades for this? With the boot screen, brightness control etc.?

Thanks!

You will only get bootscreen and brightness control with a GPU that was pulled from an iMac, but those are really expensive and will die anyway...

The best is to go with a GPU that exists on other macs. So 640M, 650M, 660M, 675MX, 680M, 750M, 755M, 775M, 780M etc... These in theory should work, but always depends on the machine it was pulled from, because they have different firmwares. If i understand it correctly, you should install Windows with bootcamp, and if your macOS won't boot, you might have better luck with Windows. And once you are there, you could try to flash different firmwares onto the gpu and see if macOS boots up with it or not. Boot screen is not that big of an issue, and you can solve brightness control with software.
 
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CuriousMacCow

macrumors newbie
Aug 12, 2018
10
0
You will only get bootscreen and brightness control with a GPU that was pulled from an iMac, but those are really expensive and will die anyway...

The best is to go with a GPU that exists on other macs. So 640M, 650M, 660M, 675MX, 680M, 750M, 755M, 775M, 780M etc... These in theory should work, but always depends on the machine it was pulled from, because they have different firmwares. If i understand it correctly, you should install Windows with bootcamp, and if your macOS won't boot, you might have better luck with Windows. And once you are there, you could try to flash different firmwares onto the gpu and see if macOS boots up with it or not. Boot screen is not that big of an issue, and you can solve brightness control with software.

Yes. Exactly what I was thinking. I’m hoping that all firmwares are the same so that I can upgrade to a 780M or a 680M atleast. I use heavy editing for video and mapping. Need a reliable default gpu system. And also, thinking of eGPU’s. What do you guys think?
 

nissart

macrumors newbie
Jul 18, 2018
3
1
I tried a second time with an other GTX 765M. This time, i've got the chime sound, fans turn on, keyboard is recognized, system looks like to start but no display, even when i plug an external monitor on the mini DP/Thunderbolt.
Led 1 and 2 are on, but led 3 (which is communication with video card) is off :(

I think this card is ok. Could it be a BIOS/firmware issue with the card ? My logic board ?
 
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vkd

macrumors 6502a
Sep 10, 2012
984
381
I tried a second time with an other GTX 765M. This time, i've got the chime sound, fans turn on, keyboard is recognized, system looks like to start but no display, even when i plug an external monitor on the mini DP/Thunderbolt.
Led 1 and 2 are on, but led 3 (which is communication with video card) is off :(

I think this card is ok. Could it be a BIOS/firmware issue with the card ? My logic board ?

If its any consolation I got exactly the same result with exactly the same card. Ended up passing it on. Playing Castlevania in a PS1 emulator instead of Doom 2017 or whatever.
 
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liquidtwitch

macrumors regular
Dec 7, 2011
116
48
Brisbane Australia
I've just tried a Quadro K3100M and the iMac's failing to boot at all. Fans spin for a bit and then nothing - only first LED lighting up on the logicboard.

Clamp is sitting fine and it doesn't look like anything is shorting so I'm guessing it was just DOA. Seller is refusing to exchange/refund though because the 'imac is unsupported', which is annoying but I only paid $80 Australian for it.
 

reix

macrumors newbie
Aug 22, 2018
1
0
Tallinn
Appologies if i have missed this but has anyone tried if Target Display Mode works with upgraded GPUs that are not Apple approved?
 

ppiMacs

macrumors newbie
Aug 23, 2018
1
0
Am i right in thinking that no one succesfully installed a 980m and got the internal display working? So 880m from an alienware is the latest gpu that works?
 
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