EOMA68 Computing Devices

by EOMA68

An Earth-friendly way to easily upgrade and fix your own computer

View all updates Nov 30, 2019

Measurements and a Hypothesis

by Luke Kenneth Casson Leighton

Though I’m now in Canada, which means I don’t have access to much test equipment, Mike is extremely supportive, and has hired an engineer, in Shenzhen, to investigate on our behalf.

I did borrow an old, analog multi-meter from a friend, and actually it turned out to provide better readings than my digital one back in Taiwan! Where previously I was getting spurious readings - resistors that I knew are 50 kΩ were reading 40 kΩ or 10 kΩ or 70 kΩ depending on surrounding components: the analog meter said, categorically, "1 kΩ" when connected to a 1 kΩ resistor. Now, it may have been a fluke, however I swear that for about one second the voltage from the SY8008B actually read 3.3 V, just as it was supposed to.

I thought about this for a while, and there is another quite simple hypothesis: the BGA balls on either the A20 or the DRAM - more likely the A20 - are shorted out. The AXP209 PMIC is detecting this, and shutting down the SY8008B. The only way to check this is with an X-ray of the assembled PCBs, so that’s what Mike is arranging. He’ll send me the images for inspection, the moment they’re available, and you’ll be able to see them in a future update.

A couple of years ago, I spent some time with an extremely knowledgeable PCB designer in Taiwan. He told me something that could be very relevant, here, about PCBs with fine-pitch BGA. PCBs are etched with acid, and when the tracks or pads are particularly close together (such as with BGA balls), not enough acid gets in to eat away the copper, and (in a very indirect way) the BGA pads end up being far larger than they should be. This, in turn, means that when the IC is put on the PCB and heated up, the BGA balls (which are made of solder) will spread out much farther, and potentially even spread so far that they contact each other and short out.

With the production PCBs being done in a different fashion from the prototyping ones, there is the outside possibility that the BGA pads have turned out "oversized." It’s just one of those weird things of PCB manufacturing.

Thank you for being so patient.

Again: apologies to people who keep asking "when will I receive my shipment?" - the answer has to be, "when all the unknown and unknowable issues have been investigated and eliminated, one at a time."

This is just how it is.

Normally, a mass-volume product, made by a proprietary business, would never, under any circumstances, announce the product until it was absolutely and definitely final and already in the mass-volume production pipeline, almost on the shelves. Their "reputation" would be "destroyed," their customers would panic if the slightest word got out of "problems," and so absolute total secrecy is the utmost priority.

Crowdfunding, on the other hand, is radically different: you back the idea, and the story and the journey is what you get to see, no matter what happens: in fact telling people exactly what happens is extremely important!

I’m grateful to those people who get it and say "thank you" for the level of detail and the description of the experiences that we’ve had, because for their project, they then know what to expect, and enjoy being educated on the kinds of pitfalls that might occur, and how to get out of them. I learned from the OpenPandora and the OpenMoko and many other projects, and am repaying that in kind.

About the Author

Luke Kenneth Casson Leighton

 Planet Earth. Usually.

$237,697 raised

of $150,000 goal

158% Funded! Order Below

Product Choices


Libre Tea Computer Card

An EOMA68-compatible computer card with an Allwinner A20 dual core processor, 2 GB of RAM, and 8 GB of NAND flash pre-installed with the Parabola GNU/Linux-libre operating system. We expect the Libre Tea Computer Card to receive the Free Software Foundation's Respects Your Freedom (RYF) certification before the first units ship.


Practically Perfect Computer Card

An EOMA68-compatible computer card with an Allwinner A20 dual core processor, 2 GB of RAM, and 8 GB of NAND flash pre-installed with the Debian GNU/Linux operating system.


Numero Uno Computer Card

An EOMA68-compatible computer card with an Allwinner A20 dual core processor, 2 GB of RAM, and 8 GB of NAND flash pre-installed with the Devuan GNU/Linux operating system.


Getting Ahead Computer Card

An EOMA68-compatible computer card with an Allwinner A20 dual core processor, 2 GB of RAM, and 8 GB of NAND flash pre-installed with the Fedora 24 GNU/Linux operating system.


Micro Desktop Housing for Computer Card

This is a Micro Desktop base unit and power supply unit with a beautiful laser-cut stack of 3mm plywood panels that creates an aesthetically attractive tiny base unit for your Computer Cards. Excludes Computer Card, keyboard, mouse and VGA monitor.


PIY Laptop Housing Kit for Computer Card

This Print-It-Yourself (PIY) kit includes all the parts, cabling and boards (main, power, and controller, assembled and tested), and battery, charger, keyboard, LCD, and CTP-LCD for trackpad that are needed to build a complete Libre Laptop once you 3D print the enclosure from the freely available GPLv3+ licensed plans. Excludes Computer Card.


PFY Laptop Housing Kit for Computer Card

This Printed-For-You (PFY) kit has everything needed to create a full EOMA68 Laptop, including a 3D printed set of casework parts, bamboo plywood panels, tested and assembled PCBs, cables, battery, charger, keyboard, LCD, and CTP-LCD for trackpad. Available in a variety of colors and materials. Excludes Computer Card.


Completely Assembled Laptop + Computer Card

A meticulously hand-assembled and fully-tested laptop. Includes your choice of EOMA68-A20 Computer Card and 3D-printed casework.


PCMCIA/EOMA68 Breakout Board

One PCMCIA/EOMA68 Breakout Board with one surface mount PCMCIA header, and tracks to some convenient 2.54-mm-spaced through-holes. Added by popular demand, for access, tinkering, development work, testing, etc.


Pass-through Card

A simple card that takes in HDMI and USB and passes them on. Turns a Laptop Housing into a portable, battery-powered dock for your smartphone, USB-HDMI dongle computer, and tablet, or a second screen, keyboard, and mouse for your existing laptop or desktop PC.


USB + HDMI Cable Set for Standalone Operation

Includes a Micro HDMI Type D cable and 3-way USB-OTG Host-Charger cable tested and known to work with EOMA68 Computer Cards. These are the cables you need to run a Computer Card as a standalone device without the need for a housing. Also useful with the Micro Desktop or Laptop Housing to add a second screen and extra USB port.



We make the modular, upgradable, Earth-friendly EOMA68 laptop.

Luke Kenneth Casson Leighton


Christopher Waid


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