Everybody loves the Raspberry Pi 400, but could it be better? One enterprising hacker with a Reddit account thought it could, identifying the all-in-one computer’s 4GB of RAM as something that could be improved, and chose a very hands-on way of doing it.
Firstly, where do you get 8GB of RAM that’s compatible with a Raspberry Pi 400? From another Raspberry Pi of course. The hacker, known as Pi-800, shows in their post how they removed the memory chip from a Raspberry Pi Compute Module 4, then replaced all 200 balls (each 0.3mm in diameter) of the ball grid array (BGA) with the judicious use of a hot air rework station and plenty of flux. The chip was then placed into its new home on the Raspberry Pi 400’s circuit board (having removed the original 4GB chip first).
Amazingly, it worked. Pi-800 lists all the tools and consumables they used in their post, and gives some tips should you wish to do the same thing, such as rubbing a tiny bit of flux on the end of a single ceramic tweezer tip to allow you to pick up the individual balls. They also note that the Samsung and Micron RAM modules being swapped are not precisely the same size, meaning you can’t use the position of the chip’s casing as a reference point. They tested their transplant with the 64bit version of the Raspberry Pi OS, and the full 8GB of RAM was available and passed memtest tests.
With news of a new Raspberry Pi OS with a 64bit version on the horizon, could an official 8GB version of the Raspberry Pi 400 be coming? We would certainly like to see that one day.