Foghorn Won't Power On (Nothing Lights Up)

You plug the Foghorn in and nothing happens: the screen stays dark, no light, no sound, the app can't find it. Before you worry that it's broken — it almost never is — check what it's plugged into.

It's the adapter, 99% of the time

The Foghorn is powered over USB-C, but it is not a USB-C "smart" device like a phone or laptop. Modern USB-C chargers (phone chargers, laptop bricks, multi-port hubs, car adapters) are smart: they wait for the device to introduce itself and ask for power before they switch any on. The Foghorn can't do that — it just takes power. So a smart adapter sits there waiting for a request that never comes, and the horn never gets a volt. It looks dead. It isn't.

The adapter that came in the box doesn't have this problem. It's a plain adapter that sends power the moment you plug in, which is exactly what the Foghorn needs. That's why we ship it with the horn, and why swapping it for "a better charger" is the single most common cause of a Foghorn that won't turn on.

Fix it

1. Use the adapter and cable that came with your Foghorn. Find the box — the adapter is the one that shipped with it. Plug the horn straight into it, straight into a wall outlet.
2. Give it 30 seconds. The screen lights up and the horn shows its boot screen.

That's it for most people. If you've lost the original adapter, contact us and we'll get you a replacement — or see the note below on what to look for.

Two tricks that often work with another adapter

If the original adapter isn't to hand, try these before anything else — they fix a surprising number of "dead" horns:

• Flip the plug. Pull the USB-C plug out of the Foghorn, rotate it 180 degrees, and push it back in. USB-C is reversible, but the power pins a smart adapter switches on can differ by orientation — one way round it may send power, the other not. Try the same flip at the adapter end too.
• Use a USB-A to USB-C cable. The old rectangular USB-A port (on a plain wall cube, a TV, a power strip with USB, a computer) always sends power — there's no negotiation on USB-A. A USB-A to USB-C cable from any phone drawer gets the Foghorn running from one of those.

Still nothing?

• Try another wall outlet. Power strips with a switch, outlets controlled by a light switch, and worn-out strips catch people out.
• Check the cable. Push the USB-C plug firmly into the Foghorn until it seats, and try a different cable — USB-C cables fail more often than adapters do.
• Look at the screen closely in a dark room. A very faint glow means it's getting power but not enough — that's a weak outlet or a damaged cable.
• Unplug for 10 seconds and plug back in. If a previous adapter left it in an odd state, a clean power-up clears it.

If the Foghorn still won't light up on its original adapter, in a known-good outlet, open a support ticket and tell us exactly which adapter and outlet you used. We'll sort out a replacement.

If you need a different adapter

Not every USB-C adapter is smart, but it's hard to tell from the outside, so the original is always the safe choice. If you must use another one, look for a simple adapter rated 5 V with a fixed output (often described as "5V 2A" or "5V 3A" — nothing about "PD", "Power Delivery", "QC" or "fast charge"). Phone fast-chargers and laptop bricks are the ones that won't work. When in doubt, ask us — we'll tell you if it'll do.