Hello! Has anyone encountered problems on the Imac 2020 27 inches with a T2 chip? I had to replace 2 T2 chips on two iMacs, the first one was successfully replaced, tested and given to the client. The second iMac after replacing the T2 is flashed, the system is installed through the target mod, it boots into the system, you can hear me tapping on the keyboard, but the image does not display (and to an external monitor). I reballed the T2 chip, changed the processor, RAM, display. No positive result! My friend said that he had 2 such devices and on both of them, after replacing the T2 boards, they either did not boot into the system or showed artifacts.Maybe this board has a factory defect? Who has encountered this?
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Answer selected by mich6el at 04-23-2025, 02:39 AM.
i have almost same problem, but for me i replaced another t2 chip instead of i reballed it...try to replace a new one again -
i have almost same problem, but for me i replaced another t2 chip instead of i reballed it...try to replace a new one againComment
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I returned my native t2 chip, but there is still no image.Comment
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This is a guide that I am writing for helping others to replace their MEC1503 EC chip if it breaks (or to get around an inconvenient prompt to the BIOS). This forum has been extremely helpful to me so I would like to contribute to help others. I will tell you right now that this task is very difficult to do. You MUST have experience and tools to do precision micro-soldering, BGA reballing, trace repair, and general laptop repair skills.
There are some specialty tools needed to do this task. The replacement MEC1503 chips can be acquired from Aliexpress. Do not buy the bare chips as... -
Common SPI bios chip programming Questions and Answers
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Q: I have a bios request,i can`t post my backup as i can`t read from the chip.
A: If you can`t read from it how do you expect to write to it ?.
Q: Why is my bios chip unreadable ?.
A: The programmer is faulty or has a worn or broken zif socket.
The USB cable is frayed,connector pins worn or some other physical damage.
Not enough amperage or voltage to power the programmer properly.
Bad...09-02-2021, 04:40 PM -
Long story short:
- dad converted Asus Chromebox CN62 into Windows compatible, with mrchromebox BIOS, years and years ago
- gave the computer to his son a couple years later
- son now decided to revert it to Chrome OS, to sell it as original (re-writing BIOS with the backup one created by his dad)
- too lazy to remove the board from the case, thought a voltage regulator was the BIOS chip (you know... it has 8 legs)
(seems like the story was not that short)
He used alligator clips to read the chip. No luck reading it. Removed chip and placed on a SOC-8... -
Hi friends.
Please help to clean me for this bios file of iMac 27" 5K 2019 (A2115 EMC 3194)
Board number 820-01236.
Pulled the bin file that i attached in this post from a normal same model iMac
But with that file in my current iMac always restarting after several minutes of operation.
And also i already tried several method to clean the me region of this file, but always end up with file system state "error" at ME Analyzer.
Any help would be appreciated.
Thanks in advance... -
Hi there, I currently have similar board with same problem. A2115 - 820-01779-3 (2020). New to Soldering and board diag.. We've located many shorted Caps using voltage injection and thermal.. This board is reading open circuit on Caps C7261-C7250 along with any other components on the PP12V_G3H_CPUCORE rail.. I however get no glowing component on the front or rear of the board.. Each of these Caps reads less than a V or Resistance when measuring directly across each one, and also beeps to ground on both sides on all of them.. This should be shorted correct? Is 1V-1.5V / 2A-5A injection to locate...
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