But what I don't know is if I can only upgrade to a low power chip (S suffix) or if I can upgrade to a full power desktop chip (no suffix). I've seen people upgrade their i5 2400S 27" iMacs to i7 2600, but I've never seen anyone tried a CPU upgrade on a 21.5" imac before let alone the highest end CPU offering from Apple on the 21.5" Mid-2011 iMac is only an i7 2600S.

Now the performance difference between the i7 2600S and i7 2600 is negligible for me, but the problem is I can't souce any i7 2600S but I can fine loads of people selling their i7 2600.

So if anyone can answer, please do as I will apreciate it greatly and if anyone is selling or knows someone who sells an i7 2600S that can ship to Indonesia please answer too. :) Thanks in advance.

⟐ Edited gennaio 31, 2024 at 9:32 GMT-7

⟐ Commented novembre 17, 2023 at 4:04 GMT-7

My iMac is not always going ON when i press Power Button, works only 20% of the time. The I have to unplug power and plug in again and try..

Diagnostic Led always ON when i plug it in, but when i press Power button then Leed 1 goes OFF and nothing happen. Sometimes when Led1 is ON and i press PowerButton it works normaly.

Powersource was cleaned and PowerOn-Button is working.

Whats the Problem? Logic Board, Power Supply?

Thanks for your help.

⟐ Answered agosto 23, 2023 at 2:36 GMT-7

⟐ Commented agosto 20, 2023 at 18:54 GMT-7

does somebody knows, the screws that fit the iMac Pro stand/leg mount?

Thank you for your help. :)

Kind regards

Peter

⟐ Answered marzo 28, 2023 at 1:01 GMT-7

Well, I got the whole thing working. I ran a switch to ground the PS_ON line as required, which activates the stock PSU. The PSU has several 12V outputs, so one of them powers the LCD driver board, another goes through a converter to provide 5V to the backlight-on signal, and another gets converted to 3.3V for a PWM module to control the backlight brightness at 150 kHz.

The LCD driver board had its own power supply for the backlight, but some reviews said it asn’t as bright as the stock one so I added the PWM module to drive the stock one.

⟐ Answer edited marzo 02, 2023 at 15:11 GMT-7

⟐ Commented gennaio 25, 2023 at 6:02 GMT-7

I opened the iMac and noticed that LED #1 stays on but when I press the power button to try and turn on the iMac, LED #2 never turns on.

I can hear the HDD spin up when I power on the iMac but no fans turn on. So I’m not sure if the PSU is bad or not.

I tried to power on the iMac with everything put together, without an HDD, and without RAM, LED #2 never lit up.

I ran a test on the RAM and HDD and both passed, so my question is if it is more likely to be the PSU being bad, the cable to the logic board being bad, the logic board being bad, or the CPU being bad.

Thank you.

⟐ Answered dicembre 27, 2022 at 15:11 GMT-7

I did the disassembly and followed a guide to “bake” the video card. It seemed to work as the Mac now booted up to a stable desktop. To test the repair, I left it on for 3-4 days and it would always come out of sleep. I noticed that there was a software update, so I did the update (High Sierra 10.13.6). Since this update, the machine will boot up to the desktop, work fine for a few minutes, then get a sleep window (randomly) and turn off. Before the “bake”, the iMac would get about 50% through the startup, present a solid gray screen and re-boot automatically in a continuous loop.

Is this just a different symptom of the GPU video card or is this another isolated issue as the machine now completes the boot cycle? Any suggestions on more in depth diagnosis?

⟐ Answered giugno 17, 2022 at 23:30 GMT-7

⟐ Answered maggio 23, 2021 at 10:29 GMT-7

I have the SATA thermal adapter cable, frame and new adhesive strips

The things stated here are true but the big question is "Will an SSD in place of the HDD portion of the Fusion drive work after installation?

As we know Apple, is very particular as to what will play nice with their hardware/software.

I have a 1 TB, 2.5 Samsung Pro 860 SSD to replace a Seagate ST1000DM003 HDD in a mid 2017 27" iMac, macOS 10.13.6. The SSD blade for the Fusion drive is the Apple custom 32 GB Samsung SSD on the logic board.

Any specific experience here, I would greatly appreciate. I am not interested in just adding external storage and high capacity blade storage is too expensive. Thanks in advance

⟐ Answered marzo 09, 2021 at 1:58 GMT-7

The Apple Hardware-Test says: 4SNS/1/C0000008: TLOp--124

I searched in the Web and found that it must be a Temperature Sensor connected to the LCD.

1. SMC PRAM VRAM Reset

2. I ordered a new LCD Tempsensor - replaced it but nothing changed.

3. I ordered a new V-SYNC /TempSens Cable (connected to the LED Backlightboard) nothing changed.

4. I ordered a new LCD Data Cable - nothing changed.

5. I ordered a new Logic Board + CPU - nothing changed.

So these are the steps I did until now and I don't know what to do now...

The only thing left i could imagine would be the LED-Backlightboard maybe reinstall OS or could be something wrong with the EFI, Powermangament I dont know.. Maybe someone experienced the same issue or knows how to repair it.

Everything else except Fans going wild and CPU is throttled works well.

EDIT: (This Programm is called HW-Monitor and is the only one that shows me 128° on LCD)

EDIT:

So i was away for like 2 hours and the imac was in Sleepmode when i came back i saw this:

Sadly it went back to 1.6GHZ after a short period of time.

EDIT:

So its definely reproducable. I have to put the iMac in Sleepmode for 20-30secs and when i wake it up the CPU runs normal ant turns to 1.6GHZ after 10secs. What the !&&*...

Maybe another hint. When I turn on Sleepmode the fans are stopping. NOW when i wake up the MAC TGPro is showing my some N/A Temperatures:

GPU DIODE

Platform Controller Hub DIe

As soon as these both Temperatures are availabe the Fans power up and the CPU gets throttled.

EDIT:

Tried to reinstall OS X did not help..

EDIT:

Tried to run the iMac without the LCD on a second Monitor did not work.

When i opened the iMac i noticed strange "glue" on the poweradapter:

Also i run a SystemDiagnosis which gave me the same error as the AHT:

This week i will probably bring it to an Authorized Apple Reseller and hope the can help me.

⟐ Commented gennaio 27, 2021 at 17:06 GMT-7

⟐ Commented ottobre 14, 2020 at 5:02 GMT-7

These are the things I've tried to get my screen running again:

I've replaced:

the LCD back-light cable

the LCD data cable

the LCD back-light sync

I reset the pram and smc

I shined a flashlight on the screen to see if the backlight wasn't working (this is after replacing the cable) - There was nothing on the screen.

-

The only thing that I see periodically on the screen is what I think to be an apple logo that flashes on startup.

Besides that the screen has been completely dead, no light, no pixels, nothing.

The iMac was lying on it's back with the glass off when I tried all these things.

I'm at my wits end, I have no idea what to do and why the LCD is not functioning. Please, if anyone has any clue why this is or what else I can try I would greatly appreciated the help. Thank you.

⟐ Answered ottobre 05, 2020 at 12:19 GMT-7

Im about to follow this guide :-

Link text

And im wondering. My mate says that I wont be able to set my SSD as a boot drive because Mac OSX will see it as a disk drive.

Is this true?

Just need to know

Ross

⟐ Answered ottobre 04, 2020 at 23:07 GMT-7

It goes like this:

1. Boot chime

2. White screen (Peripherals don't work)

3. White screen still (Peripherals begin to work, but this is normal as this is how long it would take usually to boot)

4. Peripherals working and white screen. Nothing more

The only thing i get an effect with is the reset of PRAM as it restarts twice like it's meant to. I have files on there I want but no backup (I know I was stupid to not backup) Any suggestions, Any suggestions at all are a huge help so It is greatly appreciated. This is the 2nd week trying to fix it and I am hoping the white screen is an LCD issue but I have no clue. Please don't mention peripherals causing issues as I have tried the apple ones that came with this iMac and I have tried no peripherals at all.

Thanks to those who reply.

⟐ Answer edited agosto 27, 2020 at 23:41 GMT-7

I would like to upgrade the NVIDIA GeForce 9400M Graphics Processors with 256MB of DDRS SDRAM of shared memory to:

A Quadro 4000 GPU card with at least 1GB of VRAM.

Is this possible?

⟐ Answered luglio 16, 2020 at 13:41 GMT-7

• 5k Late 2014
• 5k Mid 2015
• 5k Late 2015

Preferably the Late 2015 into the prior, then place a 6700k or its xeon 'equivalent' in.

⟐ Answered maggio 20, 2020 at 11:47 GMT-7

I have a iMac 4k retina with fusion drive 1 TB (SSD 24GB). In the future, it is possible that can I change the HDD for a SSD? in this case, what would happen with de SSD of 64 GB?

One question more, is it very dificult change the HDD in iMac 4k? I have seen tutorials of iMac 2013. If a change the HDD for a SSD, could it happen a problem with the fan?

I have many doubts about it, thank you very much.

⟐ Answered aprile 28, 2020 at 0:00 GMT-7

A relative shipped me a "dead" iMac (2009; 21.5"), saying that they thought it would be too expensive to repair the "motherboard". (They got a new Mac instead.)

However, when the iMac arrived, I plugged it in and booted it up in order to make my own diagnosis. Here's what I got:

Screen after booting

The mouse moves, and while the boot up seems mostly clean up until the end, at the last moment, I get only a partial "image" with some old-style static/pixelization at the bottom.

Following the tips & tricks here on this board, I plugged in an external display to confirm the source of the problem. No surprise - the external display is also static-y/pixelized.

From what I've read here so far, I am 90% certain this points to a fault in the graphics card itself.

Can anyone else kindly confirm this?

Thank you!

⟐ Commented novembre 27, 2019 at 15:34 GMT-7