I would solve it. to get some value to be able to sell it.
but I would not buy a new tonearm. they are still in business and selling that model, have you asked for advice from MH?
what I would look for:
1st, disconnect all other connectors to the receiver, move the interconnectors away: to prove the hum is coming from the TT itself, not adjacencies to other cables.
hum started when cartridge replaced?
2. inspect tonearm wires/connectors: any part of wire without insulation? if so, a drop of liquid rubber might solve it.
solved?
3. remove 4 connectors from cartridge pins/tighten (squeeze together gently with small pliers) the 4 connectors on the tonearm wires so they are very snug when pushed onto the cartridge’s 4 pins.
solved?
4. if not, more than likely there is a problem with the tonearm wires somewhere else: 4 signal wires: perhaps some insulation got worn off by the repeated movement of the tonearm when playing/lifting up/.... rewiring the tonearm would solve that.
5. there is a 5th wire grounding the tonearm itself. if din connector, that’s the 5th pin. if not din, it’s usually a separate wire from tonearm base to ....., then on to the turntable’s ground wire to your preamp or amp’s ground connection. if possible, check it’s condition/connections.
6. oh yeah, have you verified the phono cable itself?
one way is to make a separate ground wire out of any small gauge wire, and use a simple pair of interconnects, problem gone?