Fender Jazz Bass - circuit spec & questions
Posted: Sat Aug 28, 2010 11:26 am
My friends usa Jazz Bass has got a few issues, he bought it new 3 years ago but the shop told him its not under any warranty so he wants me to repair it.
First off the neck pickup seems dead, i cant get any reading from it on the multimeter. The bridge pickup is measuring around 4K. This seems low to me?
Secondly the tone pot appears to do nothing. Checking against wiring diagrams it is wired differently, the Hot from the volume goes to the end lug (it goes to the middle on diagrams) then to the jack, it also has two caps; one going to ground as normal and one connected between the Hot lug and the centre lug
The jack is also a stereo jack and not grounded.
He bought this from new so im baffled why it has a pointless stereo jack, and cannot understand what the point is of the second capacitor unless it is to cancel out the tone pot. The dead pickup on a 3 year old expensive guitar is also very strange.
Am i missing something? Im nor familiar with the circuitry but it seems simple yet there are some pointless(?) things going on in there.
Thanks!
First off the neck pickup seems dead, i cant get any reading from it on the multimeter. The bridge pickup is measuring around 4K. This seems low to me?
Secondly the tone pot appears to do nothing. Checking against wiring diagrams it is wired differently, the Hot from the volume goes to the end lug (it goes to the middle on diagrams) then to the jack, it also has two caps; one going to ground as normal and one connected between the Hot lug and the centre lug

The jack is also a stereo jack and not grounded.
He bought this from new so im baffled why it has a pointless stereo jack, and cannot understand what the point is of the second capacitor unless it is to cancel out the tone pot. The dead pickup on a 3 year old expensive guitar is also very strange.
Am i missing something? Im nor familiar with the circuitry but it seems simple yet there are some pointless(?) things going on in there.
Thanks!