Fixed: bass output suddenly dropped

Chuffola Frets: 2125
04 Nov, 2024
Once again I seek the collective experience and wisdom of the fretboard.

Picked up a very good condition used Squier CV Precision last week for home recording. Tonight as I was playing it there was a “pop” (this may be in my mind) and the volume output dropped significantly. I’d estimate around a drop of around two thirds. I’ve also noticed that the tone control no longer has any impact.

Not a major drama but before I take the pick guard off and have a look has anyone had a similar experience?

Tone pot gone funny? Would that impact volume level? One of the pickups knackered? Any suggestions of what to look for would be welcomed, thanks!
Comments
Funkfingers Frets: 15568
05 Nov, 2024
Difficult to answer without information about what lurks beneath the pickguard.

The altered behaviour of the tone pot implies a failed ground connection somewhere. 

If your bass has been screened using copper foil, it is possible that there is a physical short somewhere. e.g. One of the pot terminals is touching the screening material.

Chuffola said:
One of the pickups knackered?
If your Squier bass has PJ pickups, governed by three pots, the jack socket may have been relocated to the edge of the instrument as a "barrel" type. The end of the barrel jack socket competes for space with the tone control. 

If your bass just has a non-original split coils P pickup with 4-conductor + shield output cable, it is possible that it has been wired for series/parallel mode switching. The output in parallel mode will be a fair bit lower than series mode.

If your bass has active electronics of any sort, a sudden drop in output is what would be expected if the PP3 were dying on its arse.


Chuffola Frets: 2125
05 Nov, 2024
Thanks - appreciate difficult to help without seeing the bass.

It has the usual split HB Precision pickups, nothing active. I'll have a look myself later today but just wondered if anything similar had happened to someone else.
Chuffola Frets: 2125
05 Nov, 2024
The equivalent of "turning it off and on again" seems to have worked. 

Took off the pickguard and had a look. Everything connected ok, no breaks. Wiggled everything a bit. Screwed it back on and it all works ok, including the tone pot.

I presume there must have been a short or a grounding issue that the wiggles have sorted? 

Anyway, nothing to see here!
ICBM Frets: 75721
05 Nov, 2024
Is there an actual ground wire from the volume pot casing via the tone pot casing to the jack ground, or does it rely on contact from the pot casings to the shielding foil?

If the latter, it's better to add the former. (Regardless of the myth of "causing a ground loop" - there's no such thing within an instrument. More grounding is better.)
Chuffola Frets: 2125
05 Nov, 2024
I'll have a look next time I'm in there and will make the amendment if needed. Cheers