Original Apple, fully tested Power Supply, Rev A with thermistor for the Power Macintosh/Performa 5200-5220,53/54/5500 Ser.
There are two Rev. A versions and one Rev. B version of the Power Supply for the 5000 series which are non-interchangeable.
• Rev. A 661-0331 with a thermistor at CN13
• Rev. A 661-0930 without a thermistor at CN13
• Rev. B 661-1117 with a thermistor at CN9