In the current paper, a retrial tandem queueing system consisting of two stations in series is investigated. Each station is represented by a single server and a limited size buffer. Customers arrive at the first station according to a Markovian Arrival Process (MAP). The service time at the first and the second server has a Phase type (PH) distribution. The novelty of the model under consideration is the presence of a common orbit for blocked customers both at the first and second stations. Unlike other few studies of retrial tandem systems with a common orbit, our model is more general and we obtain analytical results using matrix-analytic technique. We derive the sufficient conditions for existence and absence of the stationary regime in the system, calculate the steady-state distribution of the number of customers in the orbit and at the stations and derive formulas for the most significant performance measures.