My Apple Watch is flashing the Apple logo and won’t turn on.

Hi antonella41,

We see you're posting from the  Update your Apple Watch resource. Here's some troubleshooting that should help with this issue:

"If your Apple Watch won't charge, or a message on your watch says that charging with this accessory isn't supported, try these tips: 

• Make sure that you're using the Apple Magnetic Charging Cable or USB-C Magnetic Fast Charging Cable that came with your Apple Watch.
• Make sure that you plug the Apple Magnetic Charging Cable or USB-C Magnetic Fast Charging Cable all the way into the USB Power Adapter, then make sure that you plug the adapter all the way into a power outlet.
• If you use a third-party charging stand, use the charging cable that shipped in the box with your Apple Watch.
• Completely remove any plastic wrap from both sides of the charger. 
• Make sure that the back of your Apple Watch and the magnetic charger are clean.
• Reposition the back of your Apple Watch on the charger. When the charger's magnets align correctly with your Apple Watch, a green or yellow lightning bolt  should appear on the watch face.*
• Try a different Apple Watch Magnetic Charging Cable or USB-C Magnetic Fast Charging Cable, and a different USB Power Adapter. If your Apple Watch is out of power, you might need to wait a few minutes for the lightning bolt  to appear after you start charging your device. 
• If your Apple Watch still won't charge, force it to restart. Press and hold both the side button and Digital Crown for at least 10 seconds, or until the Apple logo appears."

You can check out the full resource here: If your Apple Watch won't charge or it won't turn on

If things persist you can reach out for additional support here: Get Support

Take care.