iM 4,1-14,4 2011 iMac Graphics Card Upgrade

[iPhone_se]

OK, Playing a bit with the 2010 iMAc 11,3 that I picked up cheap. It was working before I took it apart.

Installing a GTX880 in it and an SSD. Have the GRML Linux USB stick and the hard disk unplugged.

Power on, chimes, fans come on but then nothing. Screen is black (as expected) but the system never lights the light on my network switch saying the ethernet is active and my router never reports an IP address assigned.

I connected a USB keyboard and the PRAM reset sequence works as expected (e.g. chime, wait a few seconds, chime again, let go and then nothing)

BTW, I dont' see any LEDs on this motherboard like I saw on the 12,2 that I upgraded with a K3100M a while back. are they on the back side? (I even turned the lights off in the room to see if I could find some LEDs with no success.

Done for the night, will probably put the original GPU back in tomorrow to see if I didn't break something. but if you have other suggestions on how to proceed, let me know.

Suggest testing your GRML Linux usb in another mac computer if you have one to ensure it boots all the way up to the grml login prompt. Suspect it may be hanging for some reason before ethernet port activation.

 

[west125]

Hello everyone, I have an imac 21.5 2011, I bought a GPU K1000m, I overhauled the BIOS, but the screen remains black if the panel is turned off, the image output to the external display works as soon as I connect the internal display, it disappears and the screen is black, while all 4 green indicators are on. Even installed BIG sur, what else can I try to do?

 

[Ausdauersportler]

Hello everyone, I have an imac 21.5 2011, I bought a GPU K1000m, I overhauled the BIOS, but the screen remains black if the panel is turned off, the image output to the external display works as soon as I connect the internal display, it disappears and the screen is black, while all 4 green indicators are on. Even installed BIG sur, what else can I try to do?

"but the screen remains black if the panel is turned off." - I would exactly assume this.

Please post in short sentences and use some punctuation

Do all initial tests on a newly modded iMac with High Sierra before installing Big Sur...more recent macOS versions do not solve hardware issues.

 

[west125]

I tried High Sierra on all the same no changes, it remains completely black and the backlight of the inner screen appears

 

[Ausdauersportler]

I tried High Sierra on all the same no changes, it remains completely black and the backlight of the inner screen appears

If you have a second Mac/PC/iPad ready to use just enable Screen Sharing on your iMac12,1 (21.5") and try to access it remotely. If you get both screens visible on the other Mac/PC you have likely *just* a connector problem.

As I wrote so often, hardware problems cannot be solved on this thread, it is all about software.

 

[west125]

If you have a second Mac/PC/iPad ready to use just enable Screen Sharing on your iMac12,1 (21.5") and try to access it remotely. If you get both screens visible on the other Mac/PC you have likely *just* a connector problem.

As I wrote so often, hardware problems cannot be solved on this thread, it is all about software.

while the images on the TV show, do I understand correctly the problem with the connectors of the main screen?

 

[west125]

I also noticed that the 4th diode lights up about 15-30 after switching on

 

[unclemiltie]

"The LEDs are located on the bottom left of the logic board and covered with a black adhesive rubber tape. Remove the tape ad you will see them."

Thanks, will look now that I know where

"So you confirmed Ethernet was working prior to disassembly of the iMac? I have seen second hand iMacs with dead Ethernet controllers if this is the case you can use usb-Ethernet adapter."

Actually that is one thing I did not do, stupid now but I'll try my Apple USB ethernet

"Also try moving the usb stick to different ports, I have a few iMacs with failed ports and is a common problem with old iMacs."

Did that, one try was on the on-board port and one was on the port that connects with a cable to the main board

Thanks for the suggestions!

 

[unclemiltie]

Suggest testing your GRML Linux usb in another mac computer if you have one to ensure it boots all the way up to the grml login prompt. Suspect it may be hanging for some reason before ethernet port activation.

That I have done

It boots just fine on my iMac 12,2 and my 2008 MacBook Pro

 

[unclemiltie]

The LEDs are located on the bottom left of the logic board and covered with a black adhesive rubber tape. Remove the tape ad you will see them.

Found them, sneaky guys....

was a bit of a challenge to get the tape off without taking the motherboard out but I did it.

Alas I have only the first two LEDs on. Do they have the same meaning on the 11,3 as they do on the 12,2?

(I can't see the technician guide for the 11,3 and the 12,2 one is there, thus the question)

 

[unclemiltie]

First two LEDs only means (on the 12,2) that the board cannot communicate with the GPU. This GTX880 was one of my first buys and wouldnt' POST at all in the 12,2, thus trying it on this system. The 12,2 wouldn't even chime, the fans spun up for a second and then turned off.

Looks like I'm swapping out the GPU for the original.

Thanks for the location of the LEDs, that helped a lot. On the 12,2 they're right in the middle and you cant' miss them.

 

[The_Croupier]

First two LEDs only means (on the 12,2) that the board cannot communicate with the GPU. This GTX880 was one of my first buys and wouldnt' POST at all in the 12,2, thus trying it on this system. The 12,2 wouldn't even chime, the fans spun up for a second and then turned off.

Looks like I'm swapping out the GPU for the original.

Thanks for the location of the LEDs, that helped a lot. On the 12,2 they're right in the middle and you cant' miss them.

Until the card is flashed it is normal that led 2/3 are not lit.
Once flashed, if working, led 3 will light and 4 once lvds connector/lcd screen plugged in.

 

[unclemiltie]

Well... I put the original back in and LED3 comes on without the display in. But the machine won't boot. I'm out of time for the day so I'll have to take it back apart to see if I missed something.


The screen lights but I get no boot picker when I try to select the GRML stick (or a MacOS install stick)


Now I'm wondering if the GTX880 is good but I did something else wrong. Ah the trials and tribulations of playing with an old machine. Pretty soon I'll be pretty good at taking that logic board out!

 

[unclemiltie]

OK, so system is back up and running with all of the original stuff (except for the SSD) in it. Don't know what I left undone the last time but all seems to be good.

Now maybe I'll get back to trying the GTX880 since @The_Croupier suggests that maybe things were working but unflashed. Going to plug the ethernet cable in as soon as I get MacOS up and running on the new SSD to see if it works then proceed with the GTX880 again. Third time a charm?

 

[natus.w]

I also noticed that the 4th diode lights up about 15-30 after switching on

If that 4th LED comes on, that means that the LCD is active and working, so it's likely not the LCD (linked the manual for your machine, see page 27 for the mainboard light codes)

More likely you'll have to read Table of Working NVIDIA Graphics Cards -> Known Hardware Problems, you'll see that black screen with only 3 LEDs active at startup is a known problem, you'll have to use OCLP to solve this issue.

 

[west125]

If that 4th LED comes on, that means that the LCD is active and working, so it's likely not the LCD (linked the manual for your machine, see page 27 for the mainboard light codes)

More likely you'll have to read Table of Working NVIDIA Graphics Cards -> Known Hardware Problems, you'll see that black screen with only 3 LEDs active at startup is a known problem, you'll have to use OCLP to solve this issue.

I tried it all, the backlight lights up on the screen, but there are no images on the screen

 

[DerTschnig]

Did you install OCLP before installing the GPU? Did you ever use OCLP with a different GPU before? In this case boot into High Sierra without OC after PRAM reset and re install OCLP from there.

Sorry, but I will not start a - please view and correct my EFI business - here. This OCLP tool has been created to overcome all this.

EDIT:
How did you install Big Sur (I hope it was a clean installation)?
Did you add any root volume patches after finishing the installation?
Or try a PRAM reset without any changes, first.

Hi @Ausdauersportler

Clean install or clone have the same problem.
Did you add any root volume patches after finishing the installation? No
Or try a PRAM reset without any changes, first. No

Thanks

 

[west125]

I dropped the pram, everywhere there was a clean installation that on big sur that on high sierra, in both versions 4 diodes are on, and the monitor backlight appears but there is no image, there is an image on the TV

 

[Nguyen Duc Hieu]

I dropped the pram, everywhere there was a clean installation that on big sur that on high sierra, in both versions 4 diodes are on, and the monitor backlight appears but there is no image, there is an image on the TV

Imac black screen, external works fine

Hello, I have a problem with my imac. what have I done: I have a imac 27" late 2009. I had the famous white screen, so my videocard was broken. I ordered a new one. installed that one, imac works fine. I reïnstalled with Sierra and tested the imac for about a week. Today I decided that...

forums.macrumors.com

 

[west125]

Imac black screen, external works fine

Hello, I have a problem with my imac. what have I done: I have a imac 27" late 2009. I had the famous white screen, so my videocard was broken. I ordered a new one. installed that one, imac works fine. I reïnstalled with Sierra and tested the imac for about a week. Today I decided that...

forums.macrumors.com

this applies to 27 21.5 has no such mosfet

 

[unclemiltie]

Well, well.... I guess I should have really not assumed that the ethernet was working before I started this!

What possible solutions do I have to do the flashing of the vbios on the GTX880 if I don't have an ethernet? I tried an apple USB ethernet and booted the grml stick and that doesn't seem to be recognized. (if I plug the apple ethernet USB in while the system is running MacOS it works just fine)

 

[The_Croupier]

Well, well.... I guess I should have really not assumed that the ethernet was working before I started this!

What possible solutions do I have to do the flashing of the vbios on the GTX880 if I don't have an ethernet? I tried an apple USB ethernet and booted the grml stick and that doesn't seem to be recognized. (if I plug the apple ethernet USB in while the system is running MacOS it works just fine)

With a CH341a clip programmer as outlined in post 1 Questions and Answers section.
It will probably be your cheapest option.

 

[eablokker]

Well, well.... I guess I should have really not assumed that the ethernet was working before I started this!

What possible solutions do I have to do the flashing of the vbios on the GTX880 if I don't have an ethernet? I tried an apple USB ethernet and booted the grml stick and that doesn't seem to be recognized. (if I plug the apple ethernet USB in while the system is running MacOS it works just fine)

I did mine over WIFI. The linux USB stick has a WIFI setup utility that you'll need to run through and connect to your WIFI network. It does not connect automatically. You'll need to try it on a Mac with a working screen first to see how to do it and what keys to press. You can run the linux USB on another Mac with a working screen at the same time as you're flashing the GPU on another Mac. That way you can just copy the same keystrokes from the working Mac to the flashing Mac so you can see what you're doing.

 

[unclemiltie]

With a CH341a clip programmer as outlined in post 1 Questions and Answers section.
It will probably be your cheapest option.

I was afraid of that!

not that I'm not up for it, it's just more stuff to buy that I'll only use once.

 

[unclemiltie]

The linux USB stick has a WIFI setup utility that you'll need to run through and connect to your WIFI network. It does not connect automatically. You'll need to try it on a Mac with a working screen first to see how to do it and what keys to press. You can run the linux USB on another Mac with a working screen at the same time as you're flashing the GPU on another Mac. That way you can just copy the same keystrokes from the working Mac to the flashing Mac so you can see what you're doing.

Do you have any pointers on what to do to get it running. I could use my MacBook as the "other mac" and then give this a whirl. I'm not a Linux or command line type but it's not foreign to me either.