iMac GPU Upgrade Beyond Aggravation

[cabinfourus]

Hi everyone.
First I want to express my thanks to all that work hard building a vbios for these older iMacs.
I have a mid 2010 iMac with a 21.5 LCD. I have upgraded this thing with a new CPU (core i5), more ram (12 gig), and a Quadro K1000m video graphics card. I am running into some issues.
Let me first say I have read and re-read the active posts here https://forums.macrumors.com/threads/2011-imac-graphics-card-upgrade.1596614/
I followed the detailed instructions they have posted as best I could. I used flashrom to flash the new vbios to the chip on my k1000m and all went well. I used this bios-ROM
I pre loaded Hi Sierra onto my SSD drive and installed it.
When I turn on the machine I get no sounds. I do have the first two green led lights but nothing else. I have torn this thing apart several times and can't find anything. I have tried different cards (k2000m and AMD) and still have the same results. This has been a 2 month project and I am out of ideas. Can someone lead me in the right direction?
Let me also say, I am very familiar with Windows systems and their PCs. I 3d print so I am also familiar with some coding and programming. I have never tried this GPU upgrade before and am not familiar with macs. I need all the help I can get. Thanks in advance.

 

[Nguyen Duc Hieu]

Try turn on the machine with only CPU and a single RAM stick installs.
Can you still hear the chime?
From that, add one part at a time.
First SSD, then the GPU combo, then the external display, then the internal display.
If the machine stop POSTing when you add the GPU +heatsink combo, then the issue is at the GPU combo. Sometimes, during assembling, one (me twice) may knock out some components on the logic board and... you already knew what happened. This is the worst case scenario I hope you didn't encounter.

Questions:
1. How did you flash the vBIOS?
2. Can you confirm yourself that your K1000m is a working card?

 

[The_Croupier]

Youb

Hi everyone.
First I want to express my thanks to all that work hard building a vbios for these older iMacs.
I have a mid 2010 iMac with a 21.5 LCD. I have upgraded this thing with a new CPU (core i5), more ram (12 gig), and a Quadro K1000m video graphics card. I am running into some issues.
Let me first say I have read and re-read the active posts here https://forums.macrumors.com/threads/2011-imac-graphics-card-upgrade.1596614/
I followed the detailed instructions they have posted as best I could. I used flashrom to flash the new vbios to the chip on my k1000m and all went well. I used this bios-ROM
I pre loaded Hi Sierra onto my SSD drive and installed it.
When I turn on the machine I get no sounds. I do have the first two green led lights but nothing else. I have torn this thing apart several times and can't find anything. I have tried different cards (k2000m and AMD) and still have the same results. This has been a 2 month project and I am out of ideas. Can someone lead me in the right direction?
Let me also say, I am very familiar with Windows systems and their PCs. I 3d print so I am also familiar with some coding and programming. I have never tried this GPU upgrade before and am not familiar with macs. I need all the help I can get. Thanks in advance.

You should be posting this in the thread you linked to. To have any chance at help with hardware issue you need to list step by step your process, including accurate details of everything you did to diagnose and try, also add screenshot of you nvflash.

Just by going off the tiny amount of detail you have provided in your post all I can say is you have fu##ked something up!

 

[cabinfourus]

Questions:
1. How did you flash the vBIOS?
2. Can you confirm yourself that your K1000m is a working card?

I used Flashrom with my Raspberry Pi and a ch341a programmer to load the vBios onto a Winbond 256k chip. I verified the flash, removed the old bios chip from the K1000m, soldered the Winbond chip to the GPU board. I triple-checked the soldering work and double-checked the flashed vBios.

I cannot confirm the card is in working condition. I purchased it used from an eBay seller, whom I have purchased from many times without issue. I thought it may have been the card so I purchased a second card to try. The second card has the same issue. Then, I thought it could be the type of card so I purchased an original Apple GPU and tried it. Using the Apple GPU I have the same results.

After all of this, I thought the logic board could be my problem. I replaced it with a known good logic board and have the exact same results.

Being so new to Apple products, I don't know how the boot system works. I do have a copy of the technician's manual but have not gone through it yet. My thinking was that I may be trying to upgrade too much at one time. I have changed the CPU from the Core i3 to the Core i5, added the SSD drive in place of the CD/DVD drive, and added 8 extra gigabytes of ram along with the replacement of the GPU. I have gone back to the Core i3 with no luck.

List of cards I have tried:
Nvidia Quadro K1000m from a Dell M4600
Nvidia Quadro K1000m from an HP 8540w
Nvidia Quadro K2000m from a Dell Precission 4700
AMD Radeon 6750m 512MB from an unknown working iMac

ROM files I have used:
K1000m_OC by Nickey22 (not the old ROM file from the list)
K2000m_OC by Nickey22 (not the old ROM file from the list)
Original Apple bios for the AMD

Hardware I have replaced:
GPU
Logic board
Ram
changed optical drive to SSD
LCD cable
audio port cable
HD fan
wifi card
GPU cooler and temp sensor



Things I have tried:
Removed all ram (I do hear the beeping when I do this)
Removed all hard drives
Unplugged all items one at a time
I have ordered a mini display port cable to use an external display

Here is exactly what happens when I press the power button-
The first green LED is on
Press power button
The second green LED comes on
All fans are running at low RPM
The optical drive fan starts to run at full speed
After 10 seconds the CPU fan starts to run at full speed
HD fan starts running at full speed
No chime sound is heard and no video

Without any hard drive connected, will an iMac make the chime sound when powered on?
Should the logic board still boot without the GPU installed?
Once the GPU is flashed with the new ROM, should it boot, or do I need to do any further software installs? In other words, after flashing the vBios ROM from this forum (Nickey22) to the Nvidia K1000m GPU do I just install the card and my machine should boot? Or, do I need to reload a bootloader, OS, or anything special for a new install?
Could a temp sensor cause this? How would I test the sensor?

My exact procedure-
Using flashrom, a ch341a programmer, with my Raspberry Pi I flashed the ROM file created by Nicky22 found in this forum
Removed the bios chip from the K1000m and soldered a new Winbond 256k with the new vBios ROM to the board
Applied thermal paste to GPU and memory
Installed GPU
Installed Hi Sierra OS to new SSD using a different iMac
Installed new SSD in place of the optical drive using an optical drive adapter found on ifixit
reinstalled all hardware
pressed power button

Now, here is the tricky part. I am using an older 2010 case. I removed the old core 2 logic board and have updated everything to the newer mid 2010 intel board inside this older case. I don't know if this will make a difference or not but I didn't have an issue with the swap.

I can't think of anything else I have tried. At this point, it's a matter of finding what went wrong.

Just in case anyone is curious-

I am not trying to save money. I am not trying to hold on to my old PC. I started this project because I enjoy the challenge of getting it working. I am retired and spend my time building 3D printers, laser cutters, robotics, and have now ventured into the ever-so-challenging Apple world. I have been repairing iPhones and love the attention to detail Apple provides. I also repair and fly drones by DJI and Yuneec. My knowledge is not extensive but at the same time, I am no beginner. I own a lot of equipment I use to make these repairs, so I have the proper tools. I just can't seem to figure this nasty little problem out. Thanks so much for the replies. I can only hope someone who is smarter than I can help me figure this out. As one commenter said I may have fubar'd (f*&%#d up beyond all repair). Hopefully not.

Have a glorious day!!

 

[The_Croupier]

With the imac all assembled except for the LCD and HDD, use a GRML linux flash drive as noted in post 1 of the GPU thread and verify if the card is detected inbthe system.

 

[Nguyen Duc Hieu]

Here is exactly what happens when I press the power button-
The first green LED is on
Press power button
The second green LED comes on
All fans are running at low RPM
The optical drive fan starts to run at full speed
After 10 seconds the CPU fan starts to run at full speed
HD fan starts running at full speed
No chime sound is heard and no video

Without any hard drive connected, will an iMac make the chime sound when powered on?
Should the logic board still boot without the GPU installed?
Once the GPU is flashed with the new ROM, should it boot, or do I need to do any further software installs? In other words, after flashing the vBios ROM from this forum (Nickey22) to the Nvidia K1000m GPU do I just install the card and my machine should boot? Or, do I need to reload a bootloader, OS, or anything special for a new install?
Could a temp sensor cause this? How would I test the sensor?

Have a glorious day!!

I was also new to Macs, I started owning a Macs since 2019.
To my experience,
if assembled correctly, an iMac with only the logicboard, CPU, RAM should chime. (no GPU, no HDD/SSD)
Check the audio connection if it doesn't chime. Because all of the fans are spining, it should work.
Add the Apple GPU and internal LCD, the display must turn on and shows a white screen.
After a while it would show a folder icon with a question mark, indicating that the Macs couldn't find any bootable disk.
Right now you don't have any working combination to start with. It would be very hard from this point.

My experiences on a non-working iMacs:
I once had taken the upgraded GPU to try on another machine. When assembling back, the machine was bricked. Pushing the button would make the fans spin a little, then they stopped. Later on, I detected the cause as short-circuit when assembling the GPU + heatsink.

In your post, I haven't seen any mention about PRAM reset, which should be done when you change the configuration of the iMac. Push and hold Command (Windows) + Option (Alt) + P + R steady when powering on the iMac for 2~4 minutes, until you hear the chim repeat 3 times, then release the key press and let the machine boot normally.

When you open the machine and remove the logicboard out, remember to measure the CMOS battery as well, to verify it still have enough voltage to store some data.

In any case, a chime should be heard to confirm that all parts attached to the logicboard are working.

About the LED indicator:
1 LED means the PSU is providing current to the logicboard
2 LEDs means the logicboard is working
3 LEDs means the GPU is recognized. System with soldered in GPU will not have the 3rd LED
4 LEDs mean the internal LCD is connected and recognized.

 

[cabinfourus]

I was also new to Macs, I started owning a Macs since 2019.
To my experience,
if assembled correctly, an iMac with only the logicboard, CPU, RAM should chime. (no GPU, no HDD/SSD)
Check the audio connection if it's not. Because all of the fans are spining, it should work.
Add the Apple GPU and internal LCD, the display must turn on and shows a white screen.
After a while it would show a folder icon with a question mark, indicating that the Macs couldn't find any bootable disk.
Right now you don't have any working combination to start with. It would be very hard from this point.

My experiences on a non-working iMacs:
I once had taken the upgraded GPU to try on another machine. When assembling back, the machine was bricked. Pushing the button would make the fans spin a little, then they stopped. Later on, I detected the cause as short-circuit when assembling the GPU + heatsink.

In your post, I haven't seen any mention about PRAM reset, which should be done when you change the configuration of the iMac. Push and hold Command (Windows) + Option (Alt) + P + R steady when powering on the iMac for 2~4 minutes, until you hear the chim repeat 3 times, then release the key press and let the machine boot normally.

When you open the machine and remove the logicboard out, remember to measure the CMOS battery as well, to verify it still have enough voltage to store some data.

In any case, a chime should be heard to confirm that all parts attached to the logicboard are working.

About the LED indicator:
1 LED means the PSU is providing current to the logicboard
2 LEDs means the logicboard is working
3 LEDs means the GPU is recognized. System with soldered in GPU will not have the 3rd LED
4 LEDs mean the internal LCD is connected and recognized.

Thank you so much for this reply. This is exactly what I was looking for. The boot sequence was something I wasn't sure about. I put it aside for a few days to gather my thoughts and see what others had to say. I felt I needed to break from the aggravation of failure.
A PRAM reset has not been done. I plan to give this a try later today, along with going back over it all piece by piece.

 

[cabinfourus]

GRML linux flash drive

I had tried this once with one of the other cards but great advice. I will try it again with this new one.

 

[cabinfourus]

UPDATE****

I completely tore down this machine once again. I went over everything in detail. I removed all hardware except the CPU and one stick or known working ram. The two green led lights came on but no chime.
I read some of the tech manuals and found the GPU would have to be installed in order to get the chime sound as the machine won't pass the startup check. So I installed the GPU and CPU along with one stick of working ram. The two LEDs came on but no chime. I connected my ch341a programmer back to the bios chip on the GPU and check the flash. Flashrom verified the flash once again.
So..........
I removed the logic board yet again. Only this time I decided to remove the CMOS battery and let it sit overnight. I have not tried it yet but plan to today. I am not planning on using the flashed k1000m but the stock AMD card when I put it all back together. ***fingers crossed***
Here is my frustration with all of this-
I know there's a chance I have a dead GPU but I am pretty sure not all of them were dead. I have tried three other flashed Nvidia cards I tried with no luck. I also know the logic board could be toast but like the GPU it has been replaced also. I really thought I may have missed a step somewhere and was hoping it would jump out at me.
I guess my only question now is this-
What is the difference between the two ROM files listed for the K1000m card? One is labeled "old ROM" and the other is labeled "ROM"? Could I be using the wrong file?
Or-
Could it be a temp sensor? Could my CPU temp sensor or GPU temp sensor cause this problem? It would seem logical at this point of the diagnostics but I am not sure.
I must say Apple spends a lot of time and huge amounts of money trying to keep us from upgrading these older machines. This seems to be the new standard for electronics. I am a drone pilot and fly DJI and Yuneec drones. These two drone makers have multiple drones on the market and they each have their own camera and gimbal system that will not interchange with each other. If you want a newer camera you must buy the entire drone package. They do not allow upgrading their products.
It all comes down to firmware. Since firmware is in HEX or binary form it's difficult for the average coder to rewrite it. It takes months if not years to rework firmware and at my age, I don't have that kind of time to dedicate to hacking it. (LOL)
Thanks for the help and I hope your day is GRAND!!

 

[Nguyen Duc Hieu]

UPDATE****

I must say Apple spends a lot of time and huge amounts of money trying to keep us from upgrading these older machines. This seems to be the new standard for electronics. I am a drone pilot and fly DJI and Yuneec drones. These two drone makers have multiple drones on the market and they each have their own camera and gimbal system that will not interchange with each other. If you want a newer camera you must buy the entire drone package. They do not allow upgrading their products.
It all comes down to firmware. Since firmware is in HEX or binary form it's difficult for the average coder to rewrite it. It takes months if not years to rework firmware and at my age, I don't have that kind of time to dedicate to hacking it. (LOL)
Thanks for the help and I hope your day is GRAND!!

Actually, it's much harder to upgrade the MXM cards on Windows/Linux PC. 2009~2011 iMacs are quire tolerable on this aspect.

 

[cabinfourus]

Good news **UPDATE**
After triple-checking every single part I have touched, I reinstalled everything. I had removed the CMOS battery overnight and before reinstalling it I checked the voltage and found it to be within specs.
I plugged in the iMac and turned it on. I wait for the chime....
I am happy to report I now have an iMac with the upgraded GPU making the chime sound. My only issue now is that it seems to be stuck in the boot loop.

 

[Nguyen Duc Hieu]

This post lists various issues when upgrading GPU on iMac.

2011 iMac Graphics Card Upgrade

The/my incomplete list to the most common (hardware) issues (08/03/2021) some thoughts After discussing these problems from week to week again for over one year I decided not to answer any longer on such requests or posts. It is your iMac, your buying decision, your experiment and I am not the...

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