Bartolini Pre-amp Problems

[Bassman1775]

I recently completed a bass guitar build and am installing a Bartolini HR-5.4AP/918 Pre-wired Preamp and 2 Bartolini Soapbar Pickups. I installed everything according to the wiring diagrams supplied by Bartolini. I also coated the guitar cavities with copper tape for shielding. I get no sound from the guitar except an awful ground hum. I’ve double checked the wiring multiple times. I ensured that solder connections are good and not touching each other. I ended up removing all of the pots and the jack from the body so they aren’t touching the copper tape at all. The only thing touching the copper is the bare ground wire. Does anyone have any advice on what I can check next? Should I remove all of the copper tape and start there? I’ve attached the diagrams that I used for reference.

 

[Bassman1775]

I removed all of the copper tape from inside the cavities just to eliminate it. I was wiggling wires to see if I could get the hum to stop and I noticed that if I touch the volume and blend pots the hum gets really loud like I’m grounding it out with my fingers. Not sure if that helps with the troubleshooting.

 

[p12bassnut]

I've installed several Bart preamps in the past.
It sounds to me as if there is a pot terminal grounding out.
I would double check every pot terminal and make sure there is clearance between the terminal and ground (the cavity) sometimes those lugs get bent enough to just barely touch. If you find a problem just bend the lug back carefully.
Also, when installing copper shielding you have to be absolutely sure all of it is completely flat and adheres to the wood, any sticking up will touch the pot lugs.
The other issue might be two wires touching that have bad insulation or a nick, or a cold solder joint.
A problem such as yours requires very careful inspection of every single wire and connection in the cavity.
Also make sure the bridge is grounded properly.
Hope this helps...