Does it have a plug in removable headshell like a Technics SL1200? Cotton bud and alcohol cleaning all connections is a good start as per thread suggestions.
It is a good idea to clean these connections yearly say regardless.
I would hope you have somebody local to troubleshoot this? Would seem like no more than an hour labour and cheaper than a new deck.
Always thought it would be a good franchise for record shops to stock the skill to do this sort of work for people. I guess the margins on selling new inexpensive styli aren’t worth the trouble, Audio Technica do have a pro-active rep working for them in tune with the dance market.
I had something similar I think and just took it to a shop to fit the new cartridge that solved the problem. Getting those 4 wires connected was horrendous
Identified light humming only after playing for a while
Hum is there when stylus not on record so thinking its an earthing issue rather than tone arm
As its not there at 1st maybe heat ? ( although deck not warm anywhere)
I had intermittent buzz from phono connectors, swapped them back and forth to mixer finally finding it wasn’t ‘pinching’ onto male part on mixer very well. Might be worth a shufty.
