The standard salesforce applications are quite wide, and encompass call center work and marketing as well as all the sales operations.
However, it is not expected that the salesforce will engage in service issues or work. There are differently qualified personnel who carry out service work. You should not expect a sales person to repair a piece of equipment himself, even if he were the one who sold it to you.
Therefore, the answer to this question is that servicing in any form is not the accepted part of salesperson training or employment duties.