Apple Watch screen is black

Thank you for reaching out. 🤗

There appears to be a problem with the internal display panel. Only a certified Apple technician can determine the cause and offer a complete solution.

Therefore, I recommend service.

Service Checklist:

• Apple Watch service pricing.
• Check AppleCare Coverage.
• Get your Apple Watch ready for service.

Service Appointment:

• Apple Watch Service.

Contact Information:

• United States: 1-800-APLCARE.
• Contact Support.

Additional Support:

• Apple Watch Support.
• Apple Watch User Guide.
• Check Repair Status.

Good luck! 👋🏼😉

Smiliñ 😎 Brian

Have you been swimming lately? If yes, and depending on the use and age of the watch, the watch might have been damaged by water.

The Water Lock function does not enable the Water Resistance, it can just be used to expel water from the openings for the speaker and microphone.

Seals inside the watch keep the watch water resistant, but they may lose their function over time and the environment your watch has been in when swimming.

About Apple Watch water resistance - Apple Support

See this article.

If your Apple Watch won't turn on or won't charge - Apple Support