This bass had unwanted noise and the battery was draining. It had been for s reaper before hand which had not solved the problem but one of the pots had been removed and then replaced and the soldering was not good and some of the wires were burnt. I redid this to make sure there were no iffy connections then set about trying to find if there were any short circuits between the battery and ground.
I found one somewhere on the circuit board between the battery negative and ground so I bypassed this and went direct to the output. There was also an intermittent short, again between the battery negative and ground so I replaced the output.
There was a ground wired between some shielding that was not attached to anything and was flapping around in the cavity, this could have caused untold issues.
Issues like this are always tricky, so I’m always reluctant to say off the bat that it’s sorted. I’ve asked the owner to come in with his amp so we can conduct a thorough test.