iMac M1 DFU restore issue

[Stephen]

iMac turns on no drops no cracks, tried to DFU Restore the iMac, logo turns on great! however iMac turns itself off and then restarts to the (!) icon and won't post the restore. Tried thunderbolt 3 cable, tried regular USB C cable and nothing.

this is the message it gives me with the error

Unexpected device state 'DFU' expected 'RestoreOS' (Probably forced into DFU mode externally) [com.apple.MobileDevice.MobileRestore – 0xFAE (4014)].


Any thoughts what this could be? I will open it up and repair it but I am not 100% sure since this iMac doesn't use batteries and the power is working. Any suggestions.

[Stephen]

mon2 Just wanted to update the issue with this, pulled the screen apart, it was a board related issue, HOWEVER it was not the Main Logic board, it was the Daughter USB C IO board that connects to the USB ports and the main logic board, I replaced it and now it fully restored. That was my first initial thought so I went ahead and swapped it out with another iMac daughter board we had in stock and VOILA restored without issue.

[mon2]

Is it under warranty? What does Apple say? They created this product so they must know how to fix it. Start with hem first. We should not have to hack their crap everytime.

[Stephen]

Most likely not under warranty. I would assume this is why it ended up here. They said it was ruled a faulty logic board. I was wondering if you had any thoughts on what that message means. I was going to open it up and do a little investigation but nothing shows as of yet to do so until I get an idea what that message means.

[mon2]

Are you able to boot using an external media? USB stick or internet boot? Just amazing how a multi-billion dollar company can produce such unreliable crap hardware.

[Stephen]

Are you able to boot using an external media? USB stick or internet boot? Just amazing how a multi-billion dollar company can produce such unreliable crap hardware.

that is where you are wrong...multi trillion dollar company LOL but yeah sadly it won't let me boot at all since I tried the restore process I am assuming it won't let me but let me see if it sees something. I try to go into options but it just restarts over and over.

[mon2]

Yeah. I am confident that I have seen this '!' symbol fault in my many readings over the years. Is the client ok with you carving up the screen to peak inside? If the warranty is gone that would be the next step. Just be very very very careful on how deep you go with the cutting wheel. If you go too deep, the LCD will be history. The edge flex cables are just past the glue strips. Ideally use IPA (alcohol) dipped round cutting wheels from Apple (or similar on Amazon / MobileSentrix).

[Stephen]

Yeah. I am confident that I have seen this '!' symbol fault in my many readings over the years. Is the client ok with you carving up the screen to peak inside? If the warranty is gone that would be the next step. Just be very very very careful on how deep you go with the cutting wheel. If you go too deep, the LCD will be history. The edge flex cables are just past the glue strips. Ideally use IPA (alcohol) dipped round cutting wheels from Apple (or similar on Amazon / MobileSentrix).

Oh I have opened plenty of iMac 24" M1 and done board repair those were easier because I found shorts on them and fixed them I found a common short on all the M1 iMacs. I have repaired the same issue over and over a few times with ease, but this one actually turns on and doesn't let me restore it. I was considering replacing the SOC chip with a good donor board SOC chip that would have a good OS on it and maybe it would boot?

[Stephen]

mon2 Just wanted to update the issue with this, pulled the screen apart, it was a board related issue, HOWEVER it was not the Main Logic board, it was the Daughter USB C IO board that connects to the USB ports and the main logic board, I replaced it and now it fully restored. That was my first initial thought so I went ahead and swapped it out with another iMac daughter board we had in stock and VOILA restored without issue.

[teokarafou]

Oh I have opened plenty of iMac 24" M1 and done board repair those were easier because I found shorts on them and fixed them I found a common short on all the M1 iMacs. I have repaired the same issue over and over a few times with ease, but this one actually turns on and doesn't let me restore it. I was considering replacing the SOC chip with a good donor board SOC chip that would have a good OS on it and maybe it would boot?

can you tell us the common short?