Apple A1466 820-00165 issue

[Neil Ogden]

Morning all,

This is my first post here, I've come across the forum whilst trying to learn.

I have a Macbook Air A1466 with logic board 820-00165.

It has developed a problem whereby it doesnt power up at times and when it eventually does, it doesn't operate as it should (crashing applications etc.)

I've now got it to the point where I turn it on, it shows user login page and when the bar is loading, it just reboots and does the same over and over again.

So, I did some basic troubleshooting, I tried to reset the Macbook to no avail. I tried to reinstall MacOS but I got "This device does not have a serial number and requires service" error.

When I plug the macbook in, I get fan spin and PPBUS_G3H is all good at 8.6v.

What do I test next and in what order?

Thanks in advance for the support.

Neil

[mon2]

Hi.

1) Be sure the power adapter is the original unit from Apple - not a clone. Only the original power adapter will offer a soft start of the main adapter voltage.

2) Do you have the green LED enabled using your setup with the magsafe power adapter. This is important.

3) On the missing serial number, if truly required, apparently Apple has a utility to program this number onto the board - one time only. Found a link to the utility on one of the threads.

[Neil Ogden]

Hi, thanks for the reply.

I am using the original charger, and it works on an identical unit without issue.

I have orange light which turns to green indicating a full charge after being connected for some time.

I will search for the utility to reprogram the serial number.

I am convinced some hardware has failed but just trying to figure out what.

Thanks again

Neil

[mon2]

https://www.iclarified.com/81774/how...n-your-mac/amp

[reformatt]

https://www.badcaps.net/forum/troubl...ard-serializer

Muerto also has a tool for editing EFI BIOS on MAC's (change S/N, remove EFI lock etc) but need to remove the U6100 and put in a programmer etc.

https://www.badcaps.net/forum/troubl...ac-efi-toolkit

As far as the power issues go, first thing to do on these boards is a visual inspection of the components for corrosion. Quite common to see small 0201 components corroded and pads underneath gone. Common ones I've fixed are C8005 (P5V_S0 track corroded to U8005) or C1930 (PP3V3_S5 track corroded to U1930). These are repairable but you need good microsoldering skills to run jumpers etc.

[Neil Ogden]

Hi, thanks for the replies. I have managed to get the serial number back stored into the EFI Bios. But I question why this was forgotten in the 1st place. Has something failed/corrupted?

I have done the internet recovery, installed a fresh version of iOS on a new partition. I still got slow boot up and then immediate reset into Apple logo loop.

I re-flashed SMC using MuertoGB's tool. And guess what.. I can get onto the iOS now! However, the system is very slow at installing/uninstalling applications. It feels like something is still wrong. One step closer to establishing the problem...

Thanks for your continued support.

[mon2]

Hi. Could be ME issue with BIOS. Am not a BIOS person so wait on others to comment.

Also, review:

https://www.badcaps.net/forum/troubl...165-ultra-slow

[Neil Ogden]

Thanks for the reply.

I've done Apple's Diagnostic and get "PFR001" - There may be an issue with the computers firmware.

Not sure if this will be BIOS or not. I'll have a look at the thread and work through what others have done/experienced.