Help with Bang & Olufsen Beogram RX

I recently received a Beogram RX in really great condition from a family friend. It plays the newer heavyweight vinyl albums perfectly, but anything else it plays with a lot of static --- even the ones that are in mint condition.

Does anyone have any thoughts about what the problem might be? I really don't know anything about record players, and since I'm a pretty casual listener, I'm hoping to find a cheap fix for this, definitely less than $100. Right now it has an original MMC-3 cartridge on it.

Thanks for the help!