Numark TT-200 grounding issue?

[badpapa]

Been searching around and trying to find info on if this is common and nothing really found.

Borrowing my buddy's TT-200s and I'm getting a hum from one of the decks. I tried checking the cartridges on the other deck to see if it was an issue and no hum; the one that hums is grounded to the mixer but still get noise. Get it when I tried to use Scratch Live and when I just used regular vinyl (no SL box connected) and tried different outlets as well. I'm thinking it's a grounding issue but not sure how to correct it, unless it's an issue internally.

Anyone have a problem like this or can offer any help? Thanks.

[DTR]

Try taking a length of wire and touch it between your mixer's grounding post and a metal part of the tonearm base. If the hum disapperas then it is definately a grounding issue. If not, then it could be a light connection between the headshell and the tonearm contacts. Just to be sure it's the turntable and not the mixer, have you tried the noisy tunrntable on another channel of your mixer?

[DTR]

Get it when I tried to use Scratch Live

Get what, exactly? A bad ground won't show itself as noise with Serato

[badpapa]

Just any piece of wire I have around the house will do? And I did try another channel on the mixer, first thing I did in trying to figure out this problem.

Get what, exactly? A bad ground won't show itself as noise with Serato

I meant get the noise. To show that my SL box wouldn't have been the issue or anything of that.

[DTR]

Yes any bit of wire will do. In fact anything that conducts. A wire coat hanger will work.

A bad ground may affect the quality of the signal in Serato but it will not affect the sound quality. If you're getting the same noise in Serato then the problem is not the ground.

[badpapa]

Tried the wire thing and still got hum.

But I figured it out and it is that the RCA cable is bad. Didn't realize this one had RCAs in the back that could come out, so I took those out and tried a different cable (while keeping the ground connected) and there was very little hum. So I told my buddy he'll need to get new cables. Thanks for the help DTR, I really appreciate it.

Just one more question, since the ground wire doesn't run into the turntable and mounted on inside, is it possible to ground it internally? I figure not but thought I'd ask.

[DTR]

Glad you found the problem.

Just about any turntable can be grounded internally. You just have to connect the RCA screen / shield (usually from the left channel RCA, but it doesn't matter) to any convenient metal part of the tonearm assembly. If there's a solder point already for the existing ground wire then use that.