This is because the charging battery voltage in the charging treasure has dropped below 2 volts, and the charging circuit of the charging treasure has been unable to enter the charging state. The solution is to disconnect the charging treasure battery with a stable voltage directly connected to the battery, use a multimeter to measure the voltage at both ends of the battery at more than 2 volts, and then connect the charging circuit back to the charging treasure, it will only show the red light charging state. That's how my Pinwin power bank was restored.