about midi, help me out

yo, sup yall
i got my mixer and synth (roland rs-50, reaaal nice) and i need some advice from someone who uses midi, so, when i play something with my synth in midi-mode from mpc, it gets the notes, but the keyboard dont play the notes, so what could be a problem, something with synth or mpc?

oh yes, and if someone has this soundcraft spirit e6, tell me, is it always on, the power light is always on, and it's warm and there is no on/off button? =)

peace yall

You say the RS-50 gets the notes - how do you mean? Like a MIDI LED flashes? If so, that's something.
What MIDI channel are you sending on (1A, 2A, etc..?)

Have a look at http://www.roland.co.uk/faqsearchcat.asp?ID=RS-70 , the answer to "Stephen Nagy's" question on how to set up his RS for multitimbral use. Something about selecting Parts, it may be that you still have to specify which sounds for each Part MIDI Channel - not a MPC1000 problem.