CA Guitar Repair Blog: Resurrecting a Dead Ibanez GIO Bass

Sunday, January 19, 2025

Resurrecting a Dead Ibanez GIO Bass

Testing the Pickups and Controls

This Ibanez GIO four-string bass buzzes loudly but makes no sound when plugged into an amp. The bass is equipped with two humbuckers and controls for neck volume, bridge volume, and master tone. Initial checks suggest that neither the pickups nor controls are in working order.

Pickups Do Not Work

Controls Do Not Work

Evaluating Electronic Components

Following this, I scrutinize the electronics and am not too happy with what I find. For one, both the output jack and jack plate are terribly rusty. The jack plate can be saved, but the jack itself needs to be replaced. Then again, there's the three CF mini pots. Now, I have nothing against mini pots in general. However, I've had to replace these CF [Cherk Fan] pots lots of times, and dare say that they're quirky and prone to failure.

Rusty Output Jack

Badly Tarnished Jack Plate

CF 500K Neck Volume Pot

CF 500K Bridge Volume Pot

CF 500K Tone Pot

Wiring Issues

Perhaps the most serious issues lie in the wiring. To say that there are anomalies would be an understatement, methinks. There are clear signs that the wiring has been tampered with, such as disconnected wires left dangling, exposed spliced joints, and iffy resoldering. And, as expected, continuity checks with a multimeter confirm my suspicions that the integrity of the circuit has been seriously compromised.

Neck Humbucker Series Link

Disconnected Ground

Bridge Humbucker Series Link

Disconnected Wires Twisted Together

Ground Continuity Check

Work Begins

It's now time to get to work. The electronics have been totally desoldered, and the output jack assembly taken apart. Thankfully, servicing the crusty jack plate has been made easier with the help of a polishing wheel and jewelers' rouge.

Desoldered Electronics

Empty Control Cavity

Output Jack Assembly Taken Apart

Servicing the Jack Plate and Control Knobs

Fixing the Pickups

Let's tackle the pickups, then. Desoldering the two pickups has left me with a tangled mess of wires, some of which are way too short to be reused as is.

Short and Tangled Pickup Leads

As such, I've had cut away part of the cable jackets to expose fresh leads to work on. And guess what? There's a disconnected green lead buried deep within the cable, connected to nothing. In any case, being humbuckers, there are four leads and a braided ground inside each cable. These leads are colored white, black, red, and green.

Pickup Leads Separated and Identified

With the aid of my trusty multimeter, I've figured out that black is hot, red and white soldered together are the series link, and green should be soldered to the braided ground. So, all this while, the configuration was correct, except for the disconnected green lead.

Pickup Leads Reconfigured

OK then, I've the reconfigured the wiring for both pickups. Here's the neck humbucker as an example. Testing its output with a multimeter set to 0.1 DCV and nut wrench shows that the pickup now works, and it's the same for the bridge humbucker. Yes indeed, these two have come back to life. Oh, happy day!

Testing the Neck Pickup - It Works!

Completing the Job

Let's get back to the control cavity now. Replacements comprise three full-sized Alpha A500K pots and a generic output jack. Rewiring has been carried out with red [hot] and yellow [ground] silicon-jacketed wire, as I'm all out of black. As final testing through an amp has yielded pleasing results, I do declare that this dead Ibanez GIO bass has been resurrected.