The MMCx series are known to have suspension failure due to age. I would recommend to get it retipped at Axel Schürholz in Germany. It's cheaper than buying a new one at Sound Smith. Axel has done 6 MMC cartridges for me, and they are all done in very good quality. He opens the cartrigde, replaces the suspension (rubber) and puts on the needle of your choise.
His website is http://schallplattennadeln.de/
Beocenter 9300, Beogam CD50, Beocord 5500, Beomaster 3400, Beomaster 4400, 2 Beogram 4000, Beomaster 8000, 2 beogram 8002, Beovox S-75, Beovox MS150.2, Beovox RL6000, Beovox S-35, Beomaster 6000, 2 Beocord 9000, Beocord 8004, Beocord 5000, Form 1, 2x Beolink 1000, Beo4, MX3500, LS4500. Born 1993.