If you are experiencing low or no microphone inputs levels in your Yamaha PSRS950 is likely due to using a cable that is XLR to TRS instead of a XLR to TS cable. You can see the difference between the two 1/4″ style cables below.
Pro Co EXH-20 (20')
Gator GKC-1540
Gator GKB-61 (61-Key)
Lifetime Memory USB Flash Drive (4 GB)
On-Stage Stands KT7800+ Deluxe X-Style Bench
On-Stage Stands Lok-Tight Pro Double-X ERGO-LOK
Audio-Technica ATH-M20