Help! MM Sterling conundrum!

[Leathertan]

Hi everyone!

Long time viewer, first time poster. I wonder if anyone has any advice for me here.

Just got myself a lovely Musicman Sterling (standard 4H model) and after checking behind the electronics plate (nothing), the battery box (nothing), and scratch plate (nothing, it's just flat wood!) I STILL have a random 'knocking' coming from somewhere inside the body, roughly around/under the pickup. It sounds as though the loose moving part is rolling back and forth as you tilt it (imagine holding your bass flat on its back, horizontal and strings up with the headstock to your left and the rear strap-button in your right hand, then tilt/rock it towards you then away from you...!)
Now, I'm no guitar tech and I'm figuring the strings then pickup need removing but really I'm wondering if there's anyone who's had one of these apart or knows the parts involved in them and if such a problem either:
Means the pickup is f***ed and that noise is a death sentence, or
There's a thing that often can come loose and it's easy to whip back together.
It's a fleabay purchase and the vendor has been super cool, even offering a refund if it's no dice.
Thanks in advance for any help, guys and gals!
Dan.

 

[Bert]

Hi Dan,
try to tighten the trussrod a little bit and hear if it gets better.
Put a litte piece of foam at the battery.

 

[Rod Trussbroken]

.
My guess is battery movement.

 

[Leathertan]

Thanks gents. This noise is still rattling away with the battery compartment completely removed. As for truss rods..., do any components extend from the wheel adjuster back towards the bridge end at all? Only saying because it's definitely an issue somewhere behind the pickup, and I thought the truss rod pretty much stops at the wheel and goes up the neck..., not the other way. I just thought the pickup is a single solid piece with wires going out to the selector switch onwards but the knocking is like there's a metal bar loose in there or some kind of a lump of something??

 

[Leathertan]

Could the 'Phantom' coil be at play here, spooking out my bass?
OOOOooooohhH

 

[Golem]

If not the battery [and apparently not] the only other
suspect that can klunk is your PU, but thaz no death
sentence. On an SR4 the cover is not attached. On an
SR5 it is. But I don't know about the Sterling, which
is basically a 4-string SR5 [read that twice]. You may
just need to "pot" the coils inside the cover, not rocket
science. If the cover is separate, very easy. OTOH if
the PU is epoxied inside the cover, you hafta use a bit
of imagination but still no big deal.

Test if your PU has gone microphonic. With the strings
slacked and damped, test whether tapping & knocking
on the PU cover and poles comes thru the amp, which
means you gotta re-pot it. Tap/knock with non-metalic
object, like wood or such. Acoarst, you also want the
PU to "play" fairly evenly across the string set. If one
pole is seems rather dead, thaz bad news. IIRC, the
Sterling poles are not magnets. They are ferrous slugs
that carry magnetism from a ceramic bar magnet thaz
running crosswise below each row of slugs [therefor 2
bar magnets for that humbugger].

 

[Leathertan]

Cheers Golem,
That's some nice technical info there which I can get stuck into investigating. Fingers crossed it's on the easy end of the spectrum! So, is just unscrewing a pickup, taking it out to 'have a look' and then screwing it back down an easy first port of call? The pickup I can see from the outside is solid-as with no noticeable movement. Can bits just fall off in there??
Ps. Is putting up a video clip on here possible, guys? A picture (movie) tells a thousand words!

 

[MrMusashi]

it could (depending on the year it was made) be that the phantom coil was mounted behind the pickup and has come loose

look at the picture in this post:
http://forums.ernieball.com/ernie-b...ps-top-line-mms-subs-post85399.html#post85399

i hope you figure it out!

MrM

 

[Leathertan]

Aaaah! That looks like a prime suspect..., now I'm getting somewhere. Still, PU needs extracting to know either way.
I knew those Christmas cracker screwdrivers would come in handy for something!!
Cheers Musashi. ��

 

[Leathertan]

Ok, sorted!
The ghost pickup is only glued on (the underside of the humbucker) and it had just come away in there.
V. cheap fix and after a set-up with new strings she plays like new.
Cheers, all.

 

[Bert]

thanks for reply. Haven't had this coil on the screen.