My vintage RM950ED cartidge has very little sound on one track, and normal sound on the other. I changed the tonearm head with my spare Shure cartridge, and everything is normal, so I am pretty sure the problem is in the RM950ED.
Is the cartridge "dead", would a new stylus do any good, can it be repaired, is it worth messing with?
The cartridge is "dead". The cartridge has been discontinued for some time and can not be repaired.
Consider the Shure M92E as a replacement.