Managed to revive 2013 MBA except for two issues... please help!

[Sharky II]

Hi,

I managed to revive a 2013 MBA which needed a new keyboard/top case. Everything seems to be working fine with the new keyboard, I ported over the old trackpad (as well as everything else). I'm typing this from the newly fixed MBA - with the latest version of Big Sur.

Only two issues remain:

1) No boot keys work with the built in keyboard. They work with an older Apple USB wired keyboard?
2) The wifi signal is very weak and I'm sitting right next to the router. 1 bar out of 3 in the WiFi menu.

I'm getting 12Mb/s download and 10Mb/s up, compared to my rMBP 2012 which is getting 64Mb/s and 73Mb/s on the same 2.4GHz network, right beside the MBA. The MBP is on Mojave.

Any ideas what it could be? Perhaps I connected the wifi/antenna cables the wrong way around? Or is this a Big Sur issue?

I've done SMC reset and PRAM/NVRAM (using an external keyboard).

Any ideas? This laptop was saved and is meant for my girlfriend's nephew, who desperately needs it for his homework during lockdown.

Thanks!

Ed

 

[Sharky II]

Sigh, well the wifi issue was completely my fault. I didn't put the antenna cables back correctly and when screwing the bottom of the Mac back on, I shredded the antenna cables! I will add pics shortly.

I delicately plucked them out and used electrical tape to seal them up. Wifi speeds seem more in line with the MBP, with now 78Mb/sec download and 50MB/sec upload on the 2.4GHz network.

Both the MBA and MBP have 802.11n adaptors. Edit: incorrect, the MBA has 802.11ac!

Upload is still lagging behind the MBP, but I hope that's just some kind of natural variation.

Yuck, would have been a real pain if I'd made it any worse, changing the antenna cables would be a nightmare!

Still interested in why the key commands don't work during boot (option for boot selector etc).

Cheers,

Ed

 

[Audit13]

The Mid-2013 Air has Wireless AC and should run on the 5 Ghz band to get faster throughput.

 

[Sharky II]

You're right it has AC! I was just trying to compare on a level playing field.

The MBP only has 802.11n

 

[Audit13]

When you say boot keys, do you mean the option and command keys that can be pressed after hitting the power button?

 

[Sharky II]

When you say boot keys, do you mean the option and command keys that can be pressed after hitting the power button?

Yep!

Great speeds on 5GHz WiFi

 

[Audit13]

Are you sure the NVRam is being reset?

Tried disconnecting and reconnecting the keyboard and trackpad cables?

Do the option and command keys work when booted into macOS?

MacBook is running the latest bootrom?

 

[Sharky II]

Are you sure the NVRam is being reset?

Tried disconnecting and reconnecting the keyboard and trackpad cables?

Do the option and command keys work when booted into macOS?

MacBook is running the latest bootrom?

Definitely heard the double boot chime. Happy to try again. All keys working OK in MacOS!

System Firmware Version: 429.0.0.0.0
SMC Version (system): 2.13f15

 

[Audit13]

Definitely heard the double boot chime. Happy to try again. All keys working OK in MacOS!

System Firmware Version: 429.0.0.0.0
SMC Version (system): 2.13f15

NVram definitely appears to have been reset. Bootrom looks good too.

 

[Sharky II]

For anyone interested, here’s the hash I made of the WiFi antenna cables when screwing the base back on. A mix of carelessness and bad luck.

Managed to wrap them both with electrical tape and tuck them in and all seems well...

 

[Audit13]

I damaged some connectors are the end of the wire so I took wires from a cell phone and spliced them together. The connector on the end of the cell phone antenna wire is the same connector. Instead of electrical tape, I used shrink wrap.

 

[Sharky II]

Hi!

Can anyone suggest why the trackpad and mouse are non-functional at boot?

I can't use the start up keys (option to select boot drive etc) without an external USB keyboard plugged in, and although the trackpad does work once a USB installer is booted up, or internet recovery is up - the initial mouse curser to select a boot drive or to choose a WiFi network from the drop down in Internet Recovery, does not work.

The trackpad only works once the USB installer or Internet Recovery has started.

Trackpad and keyboard are perfect once the machine is booted up, also.

Please note:

1) This was a repair of a USA laptop, and I replaced it with a UK top case/keyboard
2) The repair was olive oil into the keyboard. The logic board looks clean to me.

The entire top case with keyboard was changed for one that I purchased on eBay.

I've tried PRAM/NVRAM and SMC, but I'll try again!

Thanks

 

[Sharky II]

Just a quick update. I ran the Apple hardware test and it's reporting a fault with the trackpad (and keyboard code).

They work 100% fine in the operating system.

So I think before I hand the laptop over, I might at least try swapping the trackpad ribbon cable (only ~£3), if not replace the entire trackpad, and see if that fixes the issue.

The trackpad and trackpad cable are indeed from the 'old' case, with the olive oil spillage. The trackpad was clean but the cable was indeed a bit oily, and I had to clean it up, so it kind of makes sense. However it doesn't make sense that everything works so perfectly as soon as the computer is booted up....