Know whether the caliber hand-winds
A classic 7S26 starts through automatic winding motion, while 4R and 6R families commonly support manual winding. That distinction immediately changes troubleshooting.
Intermittent running is useful information
If the watch starts after motion and dies quickly, runs only in certain positions or stops at a repeatable hand position, tell us.
Impact and water history matter
A drop, moisture event or hard knock shortly before the failure is highly relevant even if there is no obvious external damage.
Do not force it
If winding or setting suddenly feels wrong, forcing the crown can turn one problem into several. Submit the watch and describe exactly what changed.