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This is driving me crazy

Posted: Wed Jan 24, 2007 3:10 pm
by brycycle
i go the p/u for my '75 4001 back from Sergio, who diagnosed it as not needing a re-wind, but that the red wire was disconnected and it was reading strong (thanks again Segio).

dropped it in and the treble pup is functioning, but almost inaudible. i replaced all the caps, checked all the wiring/grounds (except the jacks, but about to).

there is a fair bit of ground buzz, remedied when i make contact with a metal piece.

any ideas?

Posted: Wed Jan 24, 2007 3:15 pm
by rickfan60
The jacks can cause big trouble if they are bent or dirty or both.

Posted: Wed Jan 24, 2007 3:30 pm
by rickenbrother
Did you put the ground wire from the bridge pickup in place on one of the the height adjustment screws between the spring and the surround plate?

Posted: Wed Jan 24, 2007 3:37 pm
by brycycle
Ted - cleaning up the jacks now.

Joey - yes i did.

will let you know what happens when i finish with the jacks.

thanks for the advice

Posted: Wed Jan 24, 2007 4:01 pm
by brycycle
huh - still the same problem.

Posted: Wed Jan 24, 2007 5:30 pm
by rickboy88
Bryce, one of the guys on the forum had a cold solder joint (new Ric bass) causing a ground buzz. Could this be the cause?

Posted: Wed Jan 24, 2007 5:47 pm
by brycycle
i've re-soldered every joint and i know the pups are both functioning as they are supposed to.

can a pot every be 'bad'? or should i consider replacing the wires?

i'll re-solder again incase i missed something...

any other advice or suggestions would be appreciated.

Posted: Wed Jan 24, 2007 5:56 pm
by rickboy88
Bryce, email David Calderon (Jocal62). I believe he's the person who found the cold solder joint. That doesn't appear to be the issue, but he would have a list of things to try from people attempting to help him. Couldn't hurt.

Posted: Wed Jan 24, 2007 6:11 pm
by relayer4u
Pots can fail, no doubt about it.

Posted: Wed Jan 24, 2007 6:24 pm
by rickenbrother
Have you checked the ground wire that should be soldered to the bottom of the mute bar in the tailpiece?

Posted: Wed Jan 24, 2007 7:30 pm
by brycycle
Joey - just re-soldered the entire bass. still minimal output.

i guess i'm left with the options of replacing the wires, or replacing the pots? does that sound about right?

how can i tell if a pot is to blame?

B

Posted: Thu Jan 25, 2007 2:44 pm
by jps
Did you try hot wiring the pickup straight to the output jack as a test?

Posted: Thu Jan 25, 2007 4:19 pm
by charlyg
I hot wired mine, but then I ended up in San Diego!

Posted: Thu Jan 25, 2007 4:29 pm
by brycycle
no i didn't Jeffrey, i'll give that a shot.

is there a way of determining whether a pot is 'bad'?

Posted: Thu Jan 25, 2007 5:03 pm
by charlyg
I have dealt with electronics most of my life. Pots usually do not go completely bad., Normally, they get scratchy, non linear, and noisy. Once in a while they go completely dead. Just set your ohm meter to the range of the post. hook one probe to the middle, and then to one end, turn "knob" and watch meter go up and down. Now hook to other end and repeat. If you want to know the maximum resistance of the pot, read from end to end. The "knob" setting will not change this reading.