Apple watch stuck at passcode, not able to reset, tried everything!

If you forgot your Apple Watch passcode - Apple Support

Set up your Apple Watch - Apple Support

Apple Watch Service Answer Center - Apple Support

Apple Watch - User Guide

Make an appointment at the Apple Genius Bar for service. If you need to find an Apple Store - Find a Store - Apple. Also, see How to find your nearest Apple Authorized Service Provider (AASP) or Distributor (AAD).

"Your Apple-branded or Beats-branded hardware product (“Product”) is warranted against defects in materials and workmanship for a period of ONE (1) YEAR from the date of original retail purchase (“Warranty Period”) when used in accordance with Apple`s user manuals (refer to www.apple.com/support/country). Under this warranty, you will be able to direct your claims to Apple even in situations where you purchased the Apple Product from a third party.” [Apple One (1) Year Limited Warranty – Accessory - For Apple and Beats Branded Products Only.]

There are several frequent errors which cause failure in attempting the Erase process from the watch,

• Charger not connected (you got that one)
• Pressing both buttons so the watch does a Forced Reset (the instruction is Side Button only)
• Incorrect press on the power-off slider. The method specifies a FIRM PRESS, not a long press or finger slide. (You didn’t mention getting to this stage)

My guess if you were getting a restart automatically at 10 seconds is the watch saw both the Digital Crown and the side button pressed (wrong action) and went for the Forced Reset. It is for you to decide if this was Operator Error, or if one of the buttons is stuck and the watch needs checking by Apple Service as Kappy suggests. I’m not sure if clicking the Digital Crown will change anything on the screen until you have cleared the passcode problem, but you should be able to feel it when you press. (If you don’t feel the crown move slightly try to clean by rinsing as described in How to clean your Apple Watch - Apple Support)

There are no default passcodes, the only solution is to erase the watch and setup again. If this is not working you need hands-on support from Apple’s staff support techs so setup your support call As Kappy suggests the best solution will be a Genius Bar visit if you have access to an Apple Store, because that should be a quick same day fix rather than mailing your watch.