Technics SL1200mk2 - ground noise issue

[berrie20]

I have a Technics SL1200mk2 turntable which always worked fine. But recently after replacing the old RCA cables, I noticed a ground/hum noise which only occurs in the left channel. It isn't a loud ground noise, but subtle.
The noise is also hearable when the turntable is powered off.

Things i've tried, but unfortunately didn't resolve the problem:

• Tried different RCA cables
• Applied fresh solder on the five contacts on the RCA board
• Replaced the RCA board with a new one
  
• Internal grounding
• Cleaned the headshell contacts
• Checked the wires inside the tonearm
• Connected to a different amp

Any suggestions?

 

[Bahamayellow]

Hello are u saying there is a hum in your speakers when the turn table is off. Is your phono amp a stand alone.

 

[berrie20]

No, the phono amp is not a stand alone. I'm using the phono amp from my Kenwood reciever.

When the turntable worked fine, the turntable was fitted with a red Monster RCA cable. When that cable broke, I replaced it with a Technics HiFi Interlink cable. And from then on the hum appears.

 

[WaynerN]

If you own a volt-ohm meter, you can check continuity from headshell leads thru to the RCA connectors. The white wire should only have continuity with the pin of the left RCA interconnect, the blue wire should have continuity with the outer shell of the RCA connector. Same with the right channel (red = +, green = -).

And then are we to assume that you have the ground wire attached from turntable to receiver?

 

[woodj]

And then are we to assume that you have the ground wire attached from turntable to receiver?

And/or are there any extra wires in the old cables or the new cables?