A watch that will not start when you have just finished the build is frustrating, and it is usually one of two things, both fixable at home: the battery and its connection, or the stock firmware having been overwritten.
Start with the battery and the build. Clockstar 2.0 is a kit you put together yourself, and the Li-Po battery and main circuit board are parts you fit during the build. Unplug the watch from USB before you open it, and look at the battery before you touch anything else. If it is swollen, hot, leaking or damaged in any way, stop there and read Battery and power safety before going further. Otherwise, take the screws out of the acrylic casing, check that the battery connector is fully seated on the board and that nothing has worked loose, then close the casing up, charge the battery and try again. The Build Guide on our Resources page shows how each part should sit.
If it stopped working after you coded it. CircuitBlocks does not simply load a program onto the watch. It erases the flash and writes a MicroPython image over the original watch software, and the program you wrote is itself lost whenever the device resets. A Clockstar that no longer shows the time and date or runs its alarm and stopwatch after a coding session is running that MicroPython image, not the software it shipped with. Open CircuitBlocks, connect the watch and use Restore stock firmware to put the original software back.
The restore has to be done on a computer. CircuitBlocks reaches the watch through the browser's Web Serial support, so it needs a desktop Chromium browser: Chrome, Edge or Opera. Safari and Firefox cannot connect, and phones and tablets are blocked. Use a USB cable that carries data rather than a charge-only one, and plug into the computer directly.
If it still will not start. Message us here, or email [email protected], with your order number, how long the watch had been working before it stopped, what you had done just before, and photos of the main circuit board with the casing removed. We aim to reply within 24 to 48 business hours.
On warranty, you have the statutory two-year guarantee from delivery in the EU and EEA, and a 24-month parts warranty alongside it. A part that turns out to be genuinely defective, or one that was missing from the box, is replaced free of charge. A part broken in use or during assembly is charged, and we quote the price before anything is sent.
If the restore itself will not run — the browser cannot see the device, or it stops part-way — see The firmware restore at code.circuitmess.com fails or cannot find my device.