controllers: 10x: 501-2080-xx 20x: 501-2651-xx 11x: 501-2872-xx 21x: 501-3021-xx OLC: 370-1426-03 Sbus Card: 501-2069-xx P/S OLD POWER SUPPLY 540-2465-02 1Gbyte systems (with plastics) 300-1098-03 (without plastics) NEW POWER SUPPLY 540-2465-03 2.1 and/or 4.2Gbyte systems (with plastics) 300-1098-04 (without plastics) DISC DISTRIBUTION/SUPPORT The old power supply will support a full SSA of disc (30), but only in the following configurations: 1.) 30, 1.05 Gbyte disc. 2.) 21, 2.1 or 4.2 Gbyte disc (max of 7 per tray) and the rest are 1.05 Gbyte disc. The new power supply supports a full SSA with any mixture of 1.05, 2.1 or 4.2 Gbyte disc. If you swap the old power supply for a new power supply, it can becomes an SSA1X2 with no issues.