I've just purchased a 1999 S80 T5 (2.0T, 225hp) in prestige condition. 120k km no rust and one owner since new. Only issue is my radio won't turn on and this morning the security light on the dash started blinking constant while driving. Anyone have any tipse as to troubleshooting this? I've checked all fuses in the driver side door/dash

 

Worth getting a scan of the OBD codes first!

 

do you know the security code for your radio? are you getting voltage to the radio at all? have you checked a wiring diagram for which fuse? It could be the ignition switch,wiring, fuse or the unit. You can always pull the radio out and bench test it.