Can I solder more memory into my MacBook Air?

Solution 1:

Yes, it is possible, and REWA Technology has done it and demonstrates how they did it in this video: https://youtu.be/CTsEJ49LLsQ

After taking the laptop apart, you must:

• Heat up the sealing adhesive around the two camera chips
• Remove sealing adhesive with tweezers
• Apply some BGA paste flux around the RAM chip
• Blow it with a hot air gun for 30 seconds
• Take off the RAM chips
• Solder the tin to the soldering iron and flat the bonding pads
• Clean with an anti-static wipe
• RAM chips cannot be mixed
• Blow the bonding pad with a hot air gun
• Apply some BGA paste flux to the bonding pad
• Align the RAM chip to the bonding pad
• Blow it with a hot air gun
• Solder the rest of the RAM chips to the bonding pad
• Remove the 10k resistance R2051
• Detach a 100k resistance from a broken motherboard
• Solder the detached 100k resistance to R1636
• Test both ends of the resistance for a short circuit or missing solder
• Put the pieces of the laptop back together

Solution 2:

iFixit, who is a proponent of replacing everything in your system, does not provide a guide to replace the RAM (only the entire logic board, on which the RAM is soldered). This alone should tell you that it is something that should not be attempted by users who are not professionals.

One user did ask in their forums if it was possible. Here's one response:

...to replace/upgrade/or modify those chips, we send them to factory. Precision soldering is required, it is not to be done at home (too fine a work for home, unless you have done this same exact work before and done it well everytime).

Even after factory re-work, some boards/assembly simply fail (shorted etc). Definitely not worth the risk unless you have direct access to a mother board assembly factory and someone does it for you over there.

Another user said:

In any case SMT chips as densely laid out as these are can't be desoldered and new ones desoldered by hand. You need very special gear only available at a fab house.

And a third user added:

They use a special fixture to hold the chips in place and heat both sides at the same time. Your chances is less than 20% getting it to work and heating the board without the proper masks could cause the other components to shift killing your system for sure...

Given that you can sell your (presumably functioning) existing machine for a fair amount of money, it seems like it would be much more practical to buy a new machine than take a very high chance of destroying your current one, since then it will be worth next to nothing.

Solution 3:

Or is it massively more difficult to solder new memory into a laptop than it is to solder some simple electronics project?

Yes, it is; although "massively more difficult" is almost an understatement. It's an entirely different process.

Take a close look at the Macbook Air motherboard. The RAM chips are the four large components in the red box on the left side.

You'll notice first that there are no visible solder joints on these parts. This is because these parts are mounted to the motherboard using BGA technology — the solder joints are all on the underside of the chip. They cannot be attached using a soldering iron — they are typically attached using reflow soldering, which requires specialized hardware that you almost certainly do not have access to. Inspection of BGA joints is typically performed by X-ray… which you probably don't have access to either.

You'll notice as well that there are no available positions for additional chips. Assuming that Apple uses the same PCB design for the 4GB and 8GB models — which may not be the case! — you would likely have to remove the existing memory chips and replace them with compatible higher-capacity parts. This type of rework is extremely risky; the PCB is not designed to be reheated multiple times to remove and replace parts, and the heat cycles involved may damage the board, especially if inappropriate technique is used.

As if that weren't enough, it's not even clear the machine will recognize, or even be able to use, the new memory even if it is attached properly. Standard computer DIMMS contain a small EEPROM (the SPD chip) containing data on the type of the memory present, and the timings necessary to communicate with it. This part is not appear to be present on the Macbook Air; it's likely that the timing information is stored somewhere else in the system. Since this is not a user-serviceable part, there is no documentation available on where this data might be, nor how to update it to represent your new memory.

TL;DR: It's impossible. Not just difficult; seriously, it's impossible. If you need more memory, you'll need to replace the machine.

Solution 4:

Here is video of changing memory chip on iPhone 6 with common hotair solder. It should be similar process and it does not look so impossible.. https://www.youtube.com/watch?v=2bGb5AOwp44