I have Ruined my Macbook Air

[bnd555]

I tried installing 10.12 to an external hard disk through MBA with Flash drive.
1) I inserted Unibeast Flash Drive to MBA
2) USB Hard disk to another port.
3) Selected Flash Drive for boot up and installed 10.12 on USB HDD
4) On restart selected newly installed USB HDD (EFI HDD)
5) Macbook air got into "Chime Loop" never starts again, I tried all boot options, SMC Reset, removed battery, none of these working.

You may be wondering why I did the above. I have a Hackintosh trying to install WIFI card some thing went wrong and it got into no entry Logo. I have NVMe card which doesn't allow installation with UniBeast to boot up so I tried with the MBA. Basically trying to use HDD installation to recover NVME installation.

I did a stupid thing, but I didn't know then Any help appreciated.

 

[rwillett]

Try Googling for "reinstall macbook air from internet" and choose one of them.

 

[katetem]

same problem here, plugged in my unibeast usb and started it in my macbook air, it stucks for 30 minutes. I had to shut it down, only to realize my macbook would never function again. chimes after chimes. I have reset my SMC, no luck, I tried to reset PRAM after chimes, but once again the looping chimes still exists and the Mac was responseless. Help, my warrant is expired, I don't want to pay $300 for a stupid logic board replacement...

 

[bnd555]

same problem here, plugged in my unibeast usb and started it in my macbook air, it stucks for 30 minutes. I had to shut it down, only to realize my macbook would never function again. chimes after chimes. I have reset my SMC, no luck, I tried to reset PRAM after chimes, but once again the looping chimes still exists and the Mac was responseless. Help, my warrant is expired, I don't want to pay $300 for a stupid logic board replacement...

Tried searching for a solution online, no luck yet.

 

[WonkeyDonkey]

Tried searching for a solution online, no luck yet.

Internet recovery mode.... 'Command-R' at boot time as described here.

 

[xenoshroud]

@bnd555 - i did the same thing to my MBP (in a feeble attempt to get HDMI audio working on an eGPU setup). What I can tell you from my experience is that you corrupted your EEPROM firmware chip. There are a couple ways for you to restore the ability to boot into macOS.

Method 1 - at ~$85 USD (and probably the easiest method), you can buy a Matt Card on ebay. They ship from the Netherlands so it takes roughly 10 days for it to get to the US, but I can assure you it works (I am using the once bricked computer to type this post). What it does is override the EEPROM (EFI) chip that's soldered onto the MLB. The chip connects to the SPI port (with no need to remove the MLB from the unibody enclosure - it's literally plug and play). The one flaw with this is that the serial number for your MBA will not be the same as it was before it was bricked and iCloud, iMessage, etc won't be fully functional

Method 2 - you can purchase EEPROM programmer for a macbook air and reprogram the EFI chip. This is much more difficult to do but will cost you roughly the same amount of money. You'll need to have a working computer, a clean EFI dump of your model MBA (including the EMC #) and obviously, the necessary parts to connect your second computer to the SPI port of the bricked one. Not sure of the rules to posting to other forums, so send me a PM if you want to know where I learned about how to fix this.

Ultimately Method 1 saved me $400 bucks as Apple was going to charge me $485 to send it out for repair.

 

[bnd555]

@bnd555 - i did the same thing to my MBP (in a feeble attempt to get HDMI audio working on an eGPU setup). What I can tell you from my experience is that you corrupted your EEPROM firmware chip. There are a couple ways for you to restore the ability to boot into macOS.

Method 1 - at ~$85 USD (and probably the easiest method), you can buy a Matt Card on ebay. They ship from the Netherlands so it takes roughly 10 days for it to get to the US, but I can assure you it works (I am using the once bricked computer to type this post). What it does is override the EEPROM (EFI) chip that's soldered onto the MLB. The chip connects to the SPI port (with no need to remove the MLB from the unibody enclosure - it's literally plug and play). The one flaw with this is that the serial number for your MBA will not be the same as it was before it was bricked and iCloud, iMessage, etc won't be fully functional

Method 2 - you can purchase EEPROM programmer for a macbook air and reprogram the EFI chip. This is much more difficult to do but will cost you roughly the same amount of money. You'll need to have a working computer, a clean EFI dump of your model MBA (including the EMC #) and obviously, the necessary parts to connect your second computer to the SPI port of the bricked one. Not sure of the rules to posting to other forums, so send me a PM if you want to know where I learned about how to fix this.

Ultimately Method 1 saved me $400 bucks as Apple was going to charge me $485 to send it out for repair.

Hey, thanks for such detailed explanation.

 

[bnd555]

Hey, thanks for such detailed explanation.

I found a solution for this problem, its basically bricked EFI chip, no other problem with logic board, apple do not repair component level problems so they suggest you to change the entire board. Find out your computer model and logic board number based on which you can find new EFI chip on Ebay, some of the sellers are offering to program the chip with your serial number (obviously you have to send the serial number to them, you can find from back cover). I am here with one of the service center replacing the EFI

I wont be replacing it my self, I live in India my local service stations doesn't charge more than $10 to $20, of course I will have to give them the chip. I will update once I try this if it worked.

 

[xenoshroud]

@bnd555

I wouldnt say that your EFI chip is bricked, it just needs to be reprogrammed.

Since my original post, i thought it be best to try and not use Method 1. I was able to reprogram my original EFI chip without desoldering it from the logic board. I reflashed the chip with my original information (serial number and logic board number). I am not saying that $10 to $20 isnt a bad deal, the problem is that you'll be giving them your serial# which doesnt fly well (at least for me).

 

[patheticme]

I not only did this stupid mistake to my iMac but to a friends laptop 8( (boots to chimes exactly like yours, after trying to start the Mac off of the USB Sierra installer.) stupid me! Help! Is the reprogramming (etc) of the EEPROM or EFI my only solution!?! He needs his computer by morning! Aaaaahhhh! I first did it to the computer I made the installer on, a sierra running iMac 2013 21 inch computer I fixed up. The laptop is a beautiful 128gig May, 2015 beauty and had no cause to loop due to hardware ...obviously I don't know what I'm doing...I thought I did but software stumps me!