Three Burrito Workstation PC

My old laptop was finally starting to slow down and I needed something faster to do my work.

After perusing eBay I thought it'd be possible to build a computer for dirt cheap. I bought an old, used and untested laptop motherboard with its respective heatsink for $40. I already had many of the needed materials which cut costs greatly. In the end this machine cost less than 3 burritos (40$) while scoring 7700 on cinebench r23 multicore.

Used desktops are available at similar prices but demand much more electricty. Additionally the laptop battery can act as a UPS during power outages, providing an additional 2-3 hours of heavy usage. These two factors made the upcycled laptop an attractive experiment for desktop usage.

Laptop Motherboard

Laptop heatsink fan assembly

Thermal paste / pad

SSD (double check type against mainboard model)

Laptop Charger (necessary, choose same brand mainboard to avoid needing a new charger)

Laptop Battery (optional)

M2/M3 computer bolts and nuts

USB Hub

Display Cable

Display

Mouse and Keyboard

After receiving and checking the motherboard is in good physical condition, verify that the motherboard allows you to boot to an external monitor. This is important as the motherboard may not have its internal display present.

Plug in the display cables and turn the board on to verify display out works properly. If your board doesn't have a power button plugging in the charger should turn the computer on. Some boards will accept USB-C PD as a power supply/charger.

Prior to normal usage the motherboard heatsink should always be installed. Without one temperatures become excessive in a matter of seconds.

If the CPU seems dirty gently clean it with rubbing alcohol. Let dry and apply thermal pads + heatsink. Tighten heatsink screws in a diagonal rotating pattern to help equalize pressure. Paste is also acceptable but messier. Laptop boards are smaller than CPU boards hence using pads for the convenience. (see photo for comparison of desktop cooler to entire mainboard!)

I used leftover cardboard to build an enclosure for the motherboard.

Mount the board on appropriate sized bolts for safe handling. Standoffs can be made from cardboard or plastic. (Leaving the board flat *might* be fine but all the little surface level capacitors and resistors made me nervous.)

Begin tracing the profile of the board and hole locations to design an enclosure. Pressing holes through two equal pieces of cardboard yielded a top and bottom shell. Cut out a hole on the fan intake cardboard to ensure the heatsink fan works properly. Secure the top and bottom cardboard pieces to the mainboard with bolts and nuts sandwiching the cardboard and mainboard.

The m2 SSD slots into the mainboard very similarly as on a desktop motherboard. Gently insert it into the socket at an angle and then guide it towards the hold down screw location. Installation is complete by tightening the retainer screw.

RAM was soldered onto my board so I didn't need to worry about installation. If your board has RAM slots seat with caution and make sure both sides latch in properly.

At this stage the mainboard should have everything it needs to boot: A working heatsink + fan, a case, charger, mouse/keyboard, RAM, and internal storage. If your board is lacking in ports use a hub to increase IO options. Use either the mainboards power button to turn on the machine, or if absent plug in the charger.

I've successfully installed + booted windows and have been using this device for work successfully. At load the CPU uses about 25W of power. Thank you for reading this through, I hope it has been useful :)