Put the unit in charging cradle and see if it charges.

If the unit does not charge properly, the battery holder may not be making contact with the charging pins that can be seen on the sides of the unit. Ensure that the battery compartment is seated completely and that the two metal pins/arms are clean and making a solid connection.

If either the trimmer or shaver does not come on, it may be that the batteries need charging OR the metal contacts are bent causing them to not connect. Take electronics out, inspect contacts and try again.