try $ORA_CRS_HOME/bin/onsctl debug

in your working node, racg log shows something like this?

Code:
2007-08-31 06:46:32.653: [    RACG][2540702976] [8219][2540702976][ora.oex2.ons]: Number of onsconfiguration retrieved, numcfg = 3
onscfg[0]
   {node = oex1.risc.com, port = 6201}
Adding remote host oex1.risc.com:6201
onscfg[1]
   {node = oex2.risc.com, port = 6201}
Adding remote host oex2.risc.com:6201
onscfg[2]
   {node = oex3.risc.c
2007-08-31 06:46:32.687: [    RACG][2540702976] [8219][2540702976][ora.oex2.ons]: om, port = 6201}
Adding remote host oex3.risc.com:6201
Number of onsconfiguration retrieved, numcfg = 3
onscfg[0]
   {node = oex1.risc.com, port = 6201}
Adding remote host oex1.risc.com:6201
onscfg[1]
   {node = oex2.risc.com, port = 6201}
Adding remote h
2007-08-31 06:46:32.687: [    RACG][2540702976] [8219][2540702976][ora.oex2.ons]: ost oex2.risc.com:6201
onscfg[2]
   {node = oex3.risc.com, port = 6201}
Adding remote host oex3.risc.com:6201
onsctl: ons started