I am having trouble with "slight hum" with Pioneer PL-A45D TT


So I grabbed a pristine TT (apparently not that pristine since it hums a bit") and now I have a slight hum when the needle hits the record. With that said I have tried some trouble shooting different speakers, AMPS etc and ruled out that. I have also tried cleaning contacts. I am not one for opening it up and changing things since I dont have the knowledge to do so. Any suggestions on remedy? Thanks in advance. I know this is not a Top shelf TT however it matches a Pioneer system I put together for my collection and would like to be able to use it without the hum. 
delta222
Does the phono interconnect cable have a ground wire on it? Have you grounded the TT to the phono pre-amp/pre-amp/integrated amp to which you are connecting the phono cable?
Make sure you have a ground wire between TT/arm and preamp.
Yes I have proper connections of ground to bot TT and receiver......same problem with all 3 separate connections i tried. Most likely an internal issue one that I sadly cant fix on my own.....sad this TT is in MINT condition either its junk now or its gonna sit ....not worth having it fixed for what I paid it will cost more to fix than what I have into it. Win some lose some ....

delta222
... same problem with all 3 separate connections i tried. Most likely an internal issue one that I sadly cant fix on my own.....sad this TT is in MINT condition either its junk now or its gonna sit ...
It could be the phono cartridge itself, rather than the turntable.
Good point I will check that...