Bass guitar stays quiet !!!

I have an Ibanez 5 string electric bass guitar that went quiet. No sound when plugged in an amplifier. I checked battery, wiring connection for short & open, everything appear to be fine. There is a small rectangular PCB containing the active circuit poweted by a 9V battery. Connection is good all the way to the other end of the instrument cable. I suspect the active circuit is defective but I have no schematic, no osciloscope to check out deeper.
This bass has two soap bar shaped pickup.
Are there other things I need to check for ?

Can you bypass the circuit board and run signal through an outboard pre? If you get sound that way you'll know it's the circuit board.

Thanks for the suggestion. Each pickup has two wires, am I correct that these two wires should be connected (soldered) to an output jack ? I do have spare output jack for this test.

Next question: if the circuitry turns out to be defective, where can I look for replacement ?

Why can't we have a thread that says 'Banjo Stays Quiet'?

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Originally Posted by MikeZito

Why can't we have a thread that says 'Banjo Stays Quiet'?

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Because the word "stays" does not belong in that sentence. The banjo wasn't quiet in the first place

Quote:

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Originally Posted by Gunnar

The banjo wasn't quiet in the first place

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:) Depends on how far back in banjo history one goes. The old gut-string predecessors of modern banjos aren't likely to be anywhere near as loud as modern steel-string banjos of the last 120+ years or so. Here's an African "akonting" played by Daniel Jatta - watching his right hand leaves little doubt as to where (pre-bluegrass) clawhammer banjo style came from:

https://www.youtube.com/watch?v=lzt0v9roU6g
(or direct link)

This one is even more clawhammer-like, and also similarly not very loud:

https://www.youtube.com/watch?v=Pc9Y_uu1KH8
(or direct link)

But yeah I agree that American steel-string banjos aren't exactly noted for their quietness, :)) especially if equipped with a resonator. :disbelief: :grin:

Anyway, back to the topic... :)

Got me there.....

I would not go cutting wires if I did not thoroughly understand the circuit. Alligator clips?

Could also be a bad volume pot. The pickups should be wired to a small junction board, and from that board, should be connections to volume and tone pot(s). All output should go though these pots (depending on the wiring scheme, of course), and if the vol pot goes bad and blocks the signal, you wont get anything but silence. Rare, but it happens.

You can get decent pots from StewMac.com if you find you need to replace it/them.

Amp power switch ON ??????

Troubleshooting this on a forum can be nearly impossible. Problems like this are what I've repaired for over 20 years. The #1 fault that I see for a no output instrument is when someone tries to tighten a loose pot or an output jack and while turning the nut to tighten the component, the component spins inside the control cavity and damages or shorts the wires. Visual inspection is enough to recognize the problem. Components rarely fail but they can. Out of a thousand or so instruments, I've only seen two where a bad pot was responsible for absolutely no output.There have been an embarrassing number of instruments that only needed a new battery. On an active instrument, the problem is usually the battery connector or the output jack. If anyone has done work to the instrument, the output jack is typically miswired. If you don't have a lot of experience working on electric instruments, a good tech should be able to find and totally verify the problem in less than 30 minutes. 95% of all guitars with an active preamp turn the preamp on and off by connecting the negative side of the battery to ground when the cable is inserted into the output jack. All of these instruments have 3 lugs on the output jack, Signal, Ground, and Battery Negative, but there are exceptions. Another common problem is that some manufacturers use a cheap type of shielded wire between components and when soldering them in place, melt the insulation between the shield of the wire and the center conductor causing the signal to short to ground. As a rule, the shield of any wire should always be connected to ground and this is not only to provide noise protection but also to complete the circuit.
1. Verify the amp and cable are good using another instrument. I always do this in my shop even though its the same amp and highest quality cable I've used for years.
2. Have an open mind. The dumbest things are possible. Don't assume anything unless you've tested it including the health of the battery.
3. Visually inspect everything with good light.
4. Gently probe around with chopsticks while continuously pluck or strum the strings -- make sure every pot is CW when you do.
5. Pull the cable out of the output jack and touch the tip of the cable with your finger. Adjust the volume level of the amp so the noise is at a reasonable level. Plug the cable back in to the guitar. You should be able to hold a metal tool such as the metal shaft of a long screwdriver and touch it to the hot lug of the output jack. When you do, you should hear noise coming out of the amp -- just like if you touch the tip of the cable going into the amp. If you hear nothing, suspect a short at the jack or the wiring. There are never any dangerous voltages in an electric guitar. If you touch the center lug of the volume pot and hear noise, you can generally rule out the output jack on most instruments but there are exceptions. Anywhere in the wiring where there ought to be a signal should yield noise when you touch it.
6. Use an ohm meter. With all of the pots turned fully CW, you should not have less than 10K ohms between the ground of the jack and the signal lug.
7. Set your meter to DC volts and check that where the wires from the battery go in to the preamp, you have 9V.

Good advice above.

Always start with the most simple and work toward the complicated -- NOT, the other way around. Think of the lawnmower scene in the movie Slingblade -- "it's out of gas...."

Circuit boards rarely go bad sitting in an unused guitar.

New batteries often read less than they should -- always use a volt meter to test. Don't assume a new battery is "new."

Dirty jacks with fungus will shut down an electric. Quick test is take a piece of clean t-shirt cloth, single layer, find a screwdriver that fits the jack hole, cover the hole with cloth, squirt it with WD-40 or other electronic cleaner, stick the screwdriver in, hold the cloth around the screwdriver, turning back and forth, you'll probably get a bunch of green, brown, black fungus on your cloth, repeat with new piece of cloth until it no long comes up dirty. Test -- fixes 99 percent of guitars. A technique I developed years ago working at a vintage guitar shop -- the owners would buy vintage guitars that had not been in use for decades and find they didn't work -- almost always the jack or a pickup selector switch, which can also be cleaned with a squirt of cleaner.....if not, start looking for wires that have come off the jack or pots.....

always go with the simplest first.....

I've mostly built electric basses : active, passive, midi interface etc.....but repair anything with strings. Wrnchbnder is on the money! The only things I would add are:

1. The more 'affordable' the bass , the better the chance that the circuitboard and/or pots are junk. The OP doesn't mention what the price point is for the bass . Why manufacturers feel they need to put crap active circuits in affordable basses is beyond me. Passive pickup basses last for decades with virtually no maintenance other than spraying the pots with contact cleaner every year or so.

2. The biggest culprit are the jacks. Especially panel jacks (some call them barrel jacks) . Even good switchcraft panel jacks have a pretty short shelf for life for working bassists. Their contacts fail pretty quickly. For working musicians I'm replacing their panel jacks annually.

3. Second biggest culprit are the battery connections.

As Wrnchbndr correctly pointed out, someone with experince in active electronics can figure it out in. 1/2 hour.

Good luck.

P.s.... one of my customers has a really nice Fender all mahogany Pbass lyte. Great bass with lovely sounding pickups. Junk preamp. I put a Nordstrand 3 band with switchable midrange in that bass . Completely changed the personality of the bass.