The keyboard won't power on

Test halves individually

Disconnect the keyboard from the host device first, and then disconnect both halves from one another. Then, plug in the left half and see if it turns on and outputs characters as expected. Repeat this for the right half.

Do any of the halves work as expected? Then please follow the steps at Only one half of my keyboard works at a time.

Check for shorts

A short is what happens when two pins or pads on the PCB are connected when they should not be. You can look for blobs of solder between pins, and remove them by reworking the joints or bydesoldering.

If you suspect there's a short but aren't sure, you can use a multimeter with its continuity mode to test for shorts, too. You can refer to the schematics, for example the Aurora Series schematics and the Kyria schematics to see which pins should be connected with one another.

Microcontroller

Be sure that your microcontroller is oriented and socketed correctly. While thankfully not common, it can happen that you install the controller facing the wrong way, for example with its back side facing the keyboard instead of facing up.

Older keyboard kits, such as the Kyria rev 1 and the Kyria rev 2.0 (specifically) may have deviating controller placements. Many DIY keyboard kits also require a specific controller placement, so be sure to pay extra attention to their build guides.

RGB LEDs

Check the orientation of your RGB underglow LEDs and per-key RGB LEDs. If they are oriented the wrong way, they will cause an electrical short which causes your keyboard to not work. If you find you have oriented an LED incorrectly, you'll need to desolder it.

TRRS jacks

Have a look at both the microcontrollers and the TRRS connectors you've soldered, and read through the Soldering healthy joints page. A so-called "cold joint" can prevent your keyboard from making a reliable connection. Usually, touching it up with a hot iron and potentially a little extra solder can go a long way.

You'll want to make sure there is continuity between the right points to ensure you have no solder bridges or defective components. To check for continuity, you can use a multimeter that has a continuity check mode.

Check for continuity on the following pins, while not having the halves connected to one another:

• Each pin of the TRRS jack should connect with its corresponding pin on the other half of the keyboard. Next to that, each pin shouldn't be connected to any other pin on the same TRRS jack.
• The pins on the TRRS jack should connect with the appropriate pins on the microcontroller. You can refer to the schematics, for example the Aurora Series schematics and the Kyria schematics.

Interconnect cable

For kits requiring the use of a TRRS cable, check whether the cable is indeed a TRRS cable. Kits requiring a TRRS cable include the Elora rev 1, Kyria kits from revision 0.7 up to 1.4, and most kits not sold at splitkb.com.

If your kit is part of the Aurora Series, you can use either a TRS or a TRRS cable - the choice does not matter.

A TRRS cable has connectors which are 3.5mm in diameter, and have four shiny conductive parts: the tip, two rings and the sleeve, separated by three black rings in total. Those conductive shiny parts should have equal widths, too, where a TRS cable instead has a tip that's twice as large as the ring and the sleeve.

If you have an additional cable, you can test whether your keyboard works when using another cable. If it does work with the other cable, you may not have fully plugged in the original cable, or the original cable may be defective.