Yes, the SPS should be replaced. You can confirm its part number (P/N) with EMC support.
This morning I found this error in Navisphere:  "Standby Power Supply (Enclosure SPE SPS B) is faulted. The storage system will disable write cache.  Alert Code: 0x7404"  On the front of the SPE there is an amber light with an exclamation mark and on the back of the SPS B there are 2 amber lights, one corresponding to an exclamation mark and the other next to a crossed battery.  What does this mean, is the SPS B dead and needs replacing? The cable configuration hasn't changed  Thank you
CX3-20f SPS problem