The components in question appear to be SMD aluminum electrolytic capacitors 68uF 35V.
The YI827 or Y1827 is probably a lot number or date code.
The 68 is most likely the capacitance in microfarads (uF), 68uF is a common value.
The 35 is most likely the voltage rating, 35 volts is a common voltage rating.
The K is probably a device series or temperature rating, you would need to know the manufacture or possess the datasheet for those details.
The black stripe indicates the side of the negative terminal, these are polarized devices and must be installed the correct direction.
BigDog