Warwick diagram question

[caesarhong]

Hi,
I just got a used Warwick corvette passive. And I found that once I turned the tone all way up, a lot of buzz will come out from amp. No matter how I change the balance between the two J pickup, the buzz won't go away.
And here is a pic of the electronics:

The wired thing is there is no cable link to the "gound copper",

So, is it supposed to have a cable link to the sheet copper?
Thank you

[line6man]

All shielding needs to be grounded, otherwise you are just making things worse.

That looks like regular black paint to me, rather than conductive paint. That also kind of looks like a plastic ring around the perimeter of the control cavity?? Get out an Ohm meter and check the resistance at all the points that should be grounded. It should be zero.

(Yay! 8000 posts! I spend too much time here.)

[mmbongo]

Originally Posted by line6man

All shielding needs to be grounded, otherwise you are just making things worse.

That looks like regular black paint to me, rather than conductive paint. That also kind of looks like a plastic ring around the perimeter of the control cavity??

Never worked on a Warwick, have you?

[line6man]

Originally Posted by mmbongo

Never worked on a Warwick, have you?

Nope.

[caesarhong]

Can anyone tell me the relation between the tone control and buzz. If I turn the tone all way down, the buzz go away. once I turn the tone up, the buzz come.
As far as I know, if it is gounding issue, then the buzz should go away when I put my hand on the string, but it didn't happen. So I am confused.
And, it should not be cable issue, bez my 1977 fender has no buzz on the same cable and same amp.

[caesarhong]

Originally Posted by mmbongo

Never worked on a Warwick, have you?

You must know something, tell me plz.

[line6man]

Originally Posted by caesarhong

Can anyone tell me the relation between the tone control and buzz. If I turn the tone all way down, the buzz go away. once I turn the tone up, the buzz come.
As far as I know, if it is gounding issue, then the buzz should go away when I put my hand on the string, but it didn't happen. So I am confused.

Is this a low or high frequency buzz?

Turning a tone control all the way down removes most of the treble frequencies, so naturally, it would attenuate any high frequency noises, too.

[Rano Bass]

Do you have a closed/better pic of the output jack connections?
I'm thinking that could be where the problem is, or maybe the cable to the bridge loosened somewhere.
The little copper strip is just there to make ground with the electronics cover.

[KsPiNeSh]

Are you picking up some hum from overhead lights or electronics in the area?

[caesarhong]

Originally Posted by Rano Bass

Do you have a closed/better pic of the output jack connections?
I'm thinking that could be where the problem is, or maybe the cable to the bridge loosened somewhere.
The little copper strip is just there to make ground with the electronics cover.

Here is out jack


By the way, I just found there is a small area that not coverd by the black paint, I dont know if that could cause the buzz.

[caesarhong]

Originally Posted by KsPiNeSh

Are you picking up some hum from overhead lights or electronics in the area?

In fact, in the same room and the same position, my RockBass and 1977 Fender have no buzz, but my Fender MIM P and Warwick have buzz.

For the Fender P, it didnt have the buzz when it was new. It got buzz after I installed a pickup cover on it.

[caesarhong]

Originally Posted by line6man

Is this a low or high frequency buzz?

Turning a tone control all the way down removes most of the treble frequencies, so naturally, it would attenuate any high frequency noises, too.

Is high frequency buzz meaning gounding issue?