EFI Firmware update Sierra MacBook Air mid 2013

If the file vault or other security was enabled, the update(s) may not apply.

And to re-install seems a bit too much in this instance. If all the groundwork

was correct, it may be a simple user issue; perhaps try to install the EFI from

the stand point of "Safe mode" to see if that helps.

Usually most EFI Firmware updates are installed 'with' the later macOS.

However, why reinstall Sierra if you could instead install High Sierra 10.13.x?

That may be best, if not ideal. (I've H.S. installer saved, but not yet used.)

You may detail the other steps of non-progress to see if that rings any bells

when other readers happen across this; one may know a workable answer.

jthawk wrote:

First, High Sierras is no longer available for download. I had Sierra on one of my other computer.

It is use this link:

Get macOS High Sierra.

Upgrading to HS could solve the whole issue.

The actual screen states "Unable to verify FIRWARE"

Also of note, I installed a Lock password EFI and confirmed the same as working. After confirmation, I removed the Lock and confirmed working correctly. Thus, I have confirmed my statements of a fully functional EFI system on 820-00164-A. Secondly, the 820-3437 that also suffered the same fate was an 'Apple SSD'.

The only thing I should note that prior to the *820-3437" working I noted a difference in the screen at a point I assumed would have been firmware update the size of the Progress Bar Double (changed resolution) then install proceeded.

I can honestly say after numerous days of trying to resolve this issue for the second time I must question 'Apple dedication to support of its products.' Cleary they would rather this Mac was in the landfill and a New Air was purchased to replace it. OPINION

jhawk

Run Disk Utility on the physical drive and the boot volume.

When you performed the clean install, did you erase the internal SSD and create a GUID partition with HFS+ (Journaled) on it? I know the Mojave installer complains about not being able to update the firmware if the internal drive is formatted with APFS.

If this and the SMC & PRAM resets didn't help, then I would suggest taking the laptop to an Apple Store or Apple Authorized Service Provider to see if they can update the firmware for you. Apple just released a new BOM firmware this week to their service techs. If none of this works, then it would seem you may have a defective Logic Board.

We sadly morn the passing of my EFI chip

Sadly, folks, the issue has been located on the 820-3437-B the EFI chip has expelled solder balls on both flanks. The microscopic balls are the only clues to its unceremonious death. I would expect a new chip will cost around twenty-five dollars pre-programmed.

The good news is we now have a known issue that can be repaired and return the bench computer to its former function instead of adding to the Ewaste.

Thanks, to all for their comments and suggestions as the 'WWG1WGA' claims a collective is a powerful tool.

jhawk

The saga gets even starnger recently purcahse an early 2015 Macbook Air 11" 820-00164 and have now encountered the same problem with failure to verify firmware. Since the 820-00164 is simply the newer version of the 3437 models it seems this might be a situation that Apple should look into 820-3437 820-00165 820-00164 etc. No one has changed or removed EFI Chip it is clean and no-rework is noted. The only thing all units have in common is NVRAM reset and SMC reset since power and battery were removed in cleaning process.

Just an FYI ...

jhawk

Do you have a third party SSD installed? Your screenshot only shows orange icons indicating external drives. I know that the OWC SSDs need a firmware update installed to the SSD before Mojave will install. At least one of the OWC SSDs with the older firmware will appear as an external drive. If you have another brand of third party SSD, then you may need to install an Apple branded SSD first before the Mojave installer will update the firmware (also see my next comment). People reported this issue last year.

If the laptop's EFI firmware has not already been upgraded, then you need to partition & format the internal drive as GUID with HFS+ (Journaled) or the Mojave installer will have the "no firmware partition" error.