A solar watch uses the power of the sun's light to work, using a solar cell that absorbs energy to provide the power necessary to operate your watch. However, the solar cell can become damaged or broken, and other parts of the watch may break down, causing it to stop functioning properly. You can take some basic repair steps to fix the watch instead of going to a repair shop.
Expose the solar cell to plenty of light; the cell must absorb a certain amount of sunlight/bright light to power the watch properly.
Check the controls of the watch; whether it's digital or analog, the buttons and clock hands can slow down or stop working when the watch goes into a power-saving mode, and the watch may need to be reset to get the watch working normally again.
Remove the watch frame with the designated screwdriver stated in your manual; for example, if the manual says to only use Phillips-head screwdrivers to undo the frame, use a Phillips-head.
Check the parts for damage or wear; the watch may not function properly with parts that are bent or otherwise out of place. Clean out the visible parts gently with a cloth; however, do not move any of the parts, or touch the the circular cell battery you'll see as soon you open the watch, because only repair specialists are certified to fix those parts in these watches.
Screw the frame back in with the appropriate screwdriver to finish.