COROS Watches Bricking After Latest Update: What Happened and What to Do

I woke up to a lot of messages this week from fellow COROS users asking if they should update their watches. The answer right now: hold off. DC Rainmaker just published a piece on COROS watches bricking after the latest firmware updates, and the reports are concerning enough that I want to break down what’s happening and what you should do.

What’s Going On With COROS Firmware Updates

DC Rainmaker published an article in June 2026 titled “COROS Watch Bricking After Latest Updates” documenting multiple reports of COROS watches becoming unresponsive after installing the latest firmware. “Bricking” means the watch won’t turn on, won’t respond to button presses, and is essentially a paperweight.

This isn’t the first time COROS has had software issues. In 2025, they dealt with security vulnerability reports that raised questions about their software quality control. Now we’re seeing hardware-level failures triggered by firmware updates, which is a more serious problem because a bricked watch requires a physical fix or replacement rather than just rolling back software.

As someone who switched from Garmin to COROS specifically because I loved the simplicity and reliability, this situation is frustrating. I still think COROS makes excellent hardware, but their software update process clearly needs work.

Which Models Are Affected?

Reports in the running and triathlon communities suggest multiple COROS models have been affected, though the PACE 3 and VERTIX 2S appear most frequently in complaints. The common thread isn’t the specific model but rather the timing of the update and the conditions during installation.

COROS hasn’t released an official statement naming specific models that are vulnerable, which is part of the problem. Users are left guessing whether their specific watch is at risk. Based on community reports and COROS support page information, here’s what we know about what triggers the issue.

Symptom and Fix Table

Symptom	Likely Cause	What to Try
Watch won’t turn on after update	Update interrupted (low battery)	Hold power button 30+ seconds, connect to charger
Screen stuck on COROS logo	Firmware corruption during install	Force restart: hold both buttons for 45 seconds
Watch restarts repeatedly	Low battery during update	Charge to 100% using official cable, then force restart
Watch charges but won’t boot	Corrupted firmware partition	Contact COROS support for forced re-flash
Watch completely unresponsive	Hardware failure from bad write	Contact COROS support for replacement
Buttons register but screen is black	Display driver crash	Force restart, if no luck contact support

The most common cause according to COROS’s own support documentation is low battery during the update process. If your watch was below 50% when it started installing firmware, that’s likely what went wrong. The update process requires sustained power to write to flash memory safely, and if voltage drops during a critical write, the firmware can become corrupted.

Steps to Try Before Panicking

If your COROS watch is currently bricked or acting strange after an update, try these in order:

1. Force restart. Hold the back/lap button and the digital crown simultaneously for 45 seconds. Not 10 seconds, not 20. A full 45. Some watches need this extended hold to trigger the hardware-level reset that bypasses corrupted firmware.

2. Connect to a standard USB charger. COROS specifically recommends a standard USB 5V adapter. Don’t use a fast charger, a laptop USB port with variable voltage, or a wireless charging pad. Plug the official COROS cable into a basic 5V/1A USB adapter (the kind that came with an old phone) and leave it for at least 2 hours.

3. Try the COROS app connection. If the watch shows any signs of life (LED flashing, vibration motor), open the COROS app on your phone and see if it detects the watch. Sometimes the app can push a recovery firmware even when the screen appears dead.

4. Leave it charging overnight. Some watches that appear completely dead actually have critically depleted batteries that need extended charging before they’ll respond to any input. 8-12 hours on the charger has resolved some cases.

If none of these work after 24 hours of trying, you’re looking at a support ticket.

When to Contact COROS Support

Contact support immediately if:

• The watch was purchased from an authorized retailer and is within warranty
• You’ve tried all four steps above with no response
• The watch shows physical signs of damage (swelling battery, cracked screen)
• You get stuck in a boot loop that won’t resolve after force restart

COROS support has reportedly been responsive to bricking issues, likely because they know this is a PR problem. Have your serial number, purchase receipt, and a description of what happened ready. They may ship you a replacement or provide instructions for a forced firmware re-flash that requires specific timing of button presses during charging.

One important note from COROS’s support page: watches purchased from unauthorized marketplaces (random eBay sellers, unauthorized Amazon third-party sellers) may become unusable and won’t be covered under warranty. If you bought your COROS from a sketchy source, you might be out of luck.

Should You Delay Future Updates?

This is where I’ll give you my honest opinion as a daily COROS user. Yes, delay updates by at least a week after release. Here’s why.

COROS pushes updates aggressively compared to Garmin. Garmin tends to do staged rollouts where a small percentage of users get the update first, and only after confirming stability does it roll out widely. COROS seems to push to everyone simultaneously, which means if there’s a bug, it hits the entire user base at once.

My new protocol for COROS updates:

1. Wait 5-7 days after an update drops
2. Check Reddit, the COROS Facebook group, and DC Rainmaker’s comments for reports of issues
3. Charge the watch to 100% before starting the update
4. Use the official charging cable plugged into a standard 5V adapter
5. Don’t touch the watch during the update process
6. Keep the phone nearby with the COROS app open

This isn’t ideal. You shouldn’t have to babysit a firmware update on a $300-$500 watch. But until COROS fixes their update process, this is the reality. For a broader comparison of how different brands handle this stuff, see our Garmin vs COROS vs Apple Watch breakdown.

Does This Change My Opinion of COROS?

Honestly, a little. I still think COROS hardware is excellent and their training features are competitive with Garmin at a lower price point. But software reliability is table stakes for a GPS watch. You need to trust that your watch will work when you show up to race day.

If you’re currently shopping for a GPS watch and this incident makes you nervous, that’s valid. Garmin’s update track record is better, and Apple Watch updates are rock-solid (though you’ll burn through battery fast with GPS). Check our best GPS running watches 2026 for current recommendations across all brands.

If you already own a COROS and it’s working fine, don’t panic. Just be cautious with updates going forward. The watch you have right now is great. Just don’t rush to install the next firmware the day it drops.

For anyone weighing the value proposition of different COROS models and whether they’re still worth buying, we covered that in our COROS pricing and value guide. The hardware itself remains excellent. It’s the update process that needs fixing.

What COROS Should Do

COROS needs to implement three things immediately:

1. Staged rollouts. Don’t push firmware to every user simultaneously. Roll it out to 5% of users, wait 48 hours, check for issues, then expand.
2. Battery check before update. The watch should refuse to start an update below 60% battery. This is such an obvious safeguard that it’s baffling it isn’t already in place.
3. Recovery partition. Modern phones have recovery modes that let you reflash firmware even when the main OS is corrupted. COROS watches need something similar. A hardware-level recovery that users can trigger without sending the watch back.

Until these changes happen, COROS users are taking on more risk with each update than they should. It’s fixable, and I hope COROS fixes it quickly.

Frequently Asked Questions

Will COROS replace my bricked watch for free?

If your watch is within warranty and was purchased from an authorized retailer, COROS should replace or repair it at no cost. The bricking is caused by their firmware, not user error. Contact their support team with your serial number and proof of purchase. Watches from unauthorized sellers may not be covered.

How do I know if my COROS watch is affected?

If your watch updated recently and is still working normally, you’re fine. The bricking happens during or immediately after the update process, not days later. If your watch completed the update and rebooted successfully, you’re not at risk from that specific update.

Should I turn off automatic updates on my COROS watch?

Yes, at least temporarily. In the COROS app, you can disable automatic firmware updates and choose to install manually. This gives you time to check community reports before installing. Manual updating also lets you ensure your battery is at 100% and conditions are right before starting.

Is this a reason to switch from COROS to Garmin?

One firmware incident shouldn’t trigger a brand switch, especially since Garmin has had its own software issues over the years (including a major ransomware attack in 2020 that took services offline for days). What matters is how COROS responds. If they fix the update process and communicate transparently, this becomes a footnote. If it keeps happening, that’s a different conversation.

Can I roll back to a previous COROS firmware version?

Not easily. COROS doesn’t officially support firmware downgrades through the app. Some tech-savvy users have found workarounds involving specific button sequences during boot, but these aren’t documented by COROS and could void your warranty. Your best bet is waiting for a fix or contacting support directly.