Batboard

Our fire department is having some issues with an MCS2000. The radio is a Dual head, model 2 control heads. S split (450-512). When trying to transmit, the radio would do nothing. Radio shop checked it on site, and then removed it to take back to the shop for a bench check. They have now informed us that they are having trouble obtaining parts for this unit. If I remember right, end of support life for this model line isn't for something like another 3 years. (Please correct me if I am wrong on that) So I guess at this point, I am wondering what may be wrong with the unit itself (any frequent problems with this radio), can we still depot this unit, is that recommended and cost productive vs a new xtl, and any other help or suggestions welcome.
Thanks in advance, Ryan