No bass coming from bass amp

I suspect the jack is dicey. Although they shouldn't, the plugs on cords can vary a bit in size. Being active you may be shorting something in the switching in the jack or not making good enough contact to turn the bass on. I would open the control cavity and take a look for a loose wire, corrosion,or or poor contact.

 

@RSBass could have it. Does the bass work at all in passive mode? Is it a barrel jack or an open style? Upload a picture of the jack and also where the wires are connected in the cavity.

 

When the amp works with a guitar and that same cord does not work in the bass, while the bass works on other amps, it should be the connection. Which is weird when swapping to a different cord does not work. When the bass is plugged in, do you hear absolutely nothing?

 

Probably a faulty jack on the bass and a questionable cable.

Ive had instances where a bass would not play but another would with the same cable and amp.

If it’s the long barrel type jack they do suffer from wear and tear more than the regular type.

 

Is is possible the the GC guys tested the bass in passive mode and you are testing it in active mode? The earlier symptoms you described could be the battery running low, maybe it is dead now. Try passive mode and maybe change the battery.

 

Another possibly obvious question, the cable that doesn’t work with your bass isn’t a TRS or stereo cable is it? That type of cable won’t complete the circuit for the battery and active electronics won’t work.

 

In the pic, the cable is not fully plugged in. That would cause your problem.

 

The output jack on an active bass has two places the tip of the plug can contact. A passive instrument has one, the tip. Active uses a tip, ring, and sleeve jack. The plug can connect to the ring connection which is there to complete the circuit so the battery starts powering the pre. So you have to be sure the plug goes all the way in so the tip of the plug makes solid contact with the tip connector of the jack. If the tip only connects to the ring connector there's no signal going to the cable.

 

can you post a close up picture of the 1/4" cable end connectors?

 

The tip of the plug should only contact the longest prong of the jack. Like previous poster says, your photo shows the plug is not pushed in far enough. The plugs sleeve contacts both ground and the ring (shorter of the two prongs) on the Jack. This acts like a switch by connecting ground and ring completing your electrical connection of the battery to the negative connection of the circuit board. You do not want to leave your instrument cable plugged in to the bass when not using it as it will run the battery down.

 

Try a different cable. By the picture, it’s not plugged all the way into the jack.

 

You just need to push the jack all the way in. If it's too tight, bend the tip terminal on the output jack backward slightly so there's less tension.

 

That sounds like the tip connection of the jack is getting shorted to ground. When the nut is loose that contact is just clear of the ground (shielding paint or foil, a bare ground wire or the body of a pot for example). When the nut is tightened the tip connection touches the ground. I ran into this problem on a number of Lakland basses when the jack rotated a bit and the tip came into contact with the case of one of the pots. The solution was to rotate the jack so the tip was away from the pot and tighten it there. I also fused a bit of shrink tubing over the body of the jack so that it covered (but was not shrunk to) the tip contact - just a bit of an insulator in case the jack rotated again (it already had a lock washer to help prevent rotation).