New Epiphone Thunderbird IV Pro Ground Issue

[neuro512]

I jut purchased a vintage sunburst Epiphone Thunderbird IV Pro from MF. Had to send the first one back as there was a horrible hum which slightly improved when grounded to my hand.
Got the second one yesterday and still with the hum that improves with grounding by my hand on either the neck or the cable. Better than the first one (significantly) but still much louder than either my MIA Precision bass or my G&L L-2000. The L2K has a slight hum when maxed on treble and vol to 10 with boost (which I never play at)
My question is: Should a humbucker pickup do this? Is it because of the active circuit? Would you send this back (again!!) ??

 

[gaffster787]

be good if you could try it w/ a battery powered headphone amp or pedal to see if you bass amp/house wiring has AC issues. An active bass just exacerbates (sp?) 60 cycle hum. If still hums, then maybe the bridge is not grounded or maybe the string threads block contact w/ bridge.. just some ideas..good luck..

 

[bassplayer8953]

I also have a Tbird Pro, and like the OP, mine has a bit of a hum. Fluorescent lights seem to make it worse. And touching the metal cover on the cable, or the bridge, or the strings, seems to lessen the hum.

FWIW, it sounded like a grounding problem to me, also. I decided to check the grounding wire to the back of the bridge. The wire was laying there, not attached to anything, just sandwiched between the bridge and the body. I removed some more of the insulation, looped around 1 of the bridge hold-down screws, and re-installed everything. Seemed to lessen a bit, but it's still there. Likewise, changing the strings seemed to help...?!?!?!...but the hum is still there...although it's quiet enough now that I will play it out this way; the hum is now a fraction of what our guitarist's vintage Marshall puts out.

Also, none of my other active basses (EMG Spector, Bart's Tobias, Peavey Cirrus BXP) have any perceptible noise like the Epi does.

 

[neuro512]

Still have some time to return it to MF, so I emailed and called Gibson (their much vaunted 24-7 customer service...) and I will post any reply.

 

[pickupguy]

SOLVED: Bridge not grounded due to black paint/coating being non conductive. Sand some off to expose the bare metal.

Sorry to bring back an old thread but this is the #1 google result searching for this issue so I wanted to leave an update.

My Thunderbird also had the same bad buzzing issue. The problem was with the bridge grounding, It is common to have the ground wire sandwiched between the bridge and body as noted above, most fender hard tails are this way, but any paint or non conductive coating must be sanded off the bridge or it wont ground, Likely bringing it up against the screw as mentioned above would have helped but it would be a poor connection.