Xbox 360 203 Watt 360 power supply ?

[Ubersnarl]

Hello. I got an original 360 console only from a friend and recently bought a power supply for it only to find it of course has the rrod. Anyway I will try to tackle that later but one thing I noticed about the power supply is that it stays green for a long time after unplugging, and then goes bright red before the light completely dies. I have not noticed that before on other 360 psu's, and does not do it while system is running or when powering on. Also does not do it every time. Just wondering if this PSU is toast also. Thanks