ibanez

Red Ibanez A200 Acoustic Electric Guitar Gets Fixed Right

by

Sophia called The Unbrokenstring Crew after her prized red Ibanez acoustic/electric quit during a gig.  Could we fix it?

This is a surprisingly solid instrument, with a red finish that just won’t quit.

 

I also have a similar Chinese acoustic electric which is a surprisingly good guitar for the money.

 

The tuner still worked although the output from the guitar was silent.  Therefore, the problem is between the electronics and the output jack.  The electronics and tuner are removed to gain access.

 

That didn’t take long to find.  Someone had just soldered the wire to the connector pin.  This eventually flexed and failed.

 

The other end of the broken cable goes to the output jack.  The balanced output jack is a nice touch.

 

Let’s try to take some pics inside the guitar.  But we need more light.  This LED flashlight will do the job.

 

This is inside the guitar.  The wire tie holds the harnesses in place so that they don’t rattle while the instrument is played.

 

I didn’t need to remove the piezo pickup, but I’m taking it out of the guitar anyway so that it is not damaged.  The pickup and the tuner are one piece, so we can store them all safely while other work proceeds.

 

Meet Ms. Output Jack.

 

The broken cable solders to the circuit board.  The location and function of the wires is recorded in the notebook.

 

The unbalanced TRS output jack is wired to the circuit board as shown.  This picture is for documentation purposes.

 

Can you see a problem?  The TRS output jack should fit down inside bosses molded into the body of the output jack assembly.  Whoever tried to fix this before installed the TRS jack 90 degrees out from where it belonged.

 

This is the end of the broken cable.

 

A new cable was secured from a guitar junkyard on eBay.  Looks the same, doesn’t it?

 

The old cable was desoldered and the new one installed as shown.  We are ready to solder the wires to the PCB.

 

Soldering complete.  Note that the TRS jack, on the right, is correctly installed now.

 

The output jack goes where it belongs.

 

Before we install the electronics, let’s show a little love to the bridge with some Dr. Duck’s Axe Wax.

 

The new cable installs as shown.  I think this pic was taken while I was still testing everything out prior to reassembly.

 

I forgot to ask Sophia what gauge of strings she wanted.  These are probably 11s.

 

A phone call confirmed that these were what she wanted!  This guitar is repaired better than it was when Sophia purchased it.  The Unbrokenstring Crew makes the world just a little better than it was before.

Thanks for reading all the way to the end!

CONTACT – David Latchaw EE
281-636-8626

 

Ibanez Compressor Pedal CP10 Repair

by

Mysteriously, this pedal just went mute while playing.  Can the Unbrokenstring Crew get it going again?

I find this to be a unique design.  But I cannot help but think that the assumption was made that everyone uses their right foot to run the pedal.  Using your left foot is a little awkward.

 

Let’s make a quick tour of the unit.  The pointers on these molded knobs are actually easy to see when the unit is on the floor.  The LED indicates that the unit is in circuit and active.

 

Pushing this little tab out allows the pedal pad to open.

 

The 9v battery goes here.  This switch is actually soldered to a small circuit board underneath.

 

Removing the bottom cover exposes the circuit board.  The black shiny sheet in the middle is an insulator.

 

The circuit board tips out like this.  But, there’s more!

 

The controls are located on a smaller circuit board underneath.  Out it comes!

 

These bushings align the shafts of the controls in the holes.  They just push in like grommets.

 

Now we can get to everything.  The switch itself is left installed in the housing.

 

Troubleshooting begins, using my massive Marshall Stack as an output indicator.

 

The signal is traced to here.  And then the signal disappears.  Can you see it?  I can’t either.

 

This capacitor is open-circuit.  No signal shall pass this way again.

 

Here is a replacement.

 

The replacement goes here.

 

The new cap is soldered in and the flux is cleaned away from the board.  Because I’m OCD like that.

 

Everything is working again.  We’ll put this unit back together and do a final test!

 

This looks no different than the first picture.  Except, this one works.

Thanks for reading all the way to the end!

CONTACT – David Latchaw EE
281-636-8626

Ibanez TubeScreamer Pedal Repair

by

Steve said that his Keeley-modded Tube Screamer pedal had quit.  Could the Unbrokenstring Crew bring it back to life?

This pedal is in great shape cosmetically!

Robert Keeley made a few circuit changes that are well-documented on the Web.  This pedal has those changes.

The battery box has its own lid.

The bottom of the pedal is shielded with the metal screen seen in the center.

A die cut sheet of black insulative material protects the circuit board from the metal shield.

Let’s get it all out of the enclosure so that we can work on it.

We’ve applied battery power and connected up to my Marshall Stack.  The original problem is still with us.

An oscilloscope probe verifies that the dual operational amplifier is defective.  Part of the Keeley mod specifies a Texas Instruments 4558 dual op amp.  This IC is socketed, so replacing it is trivial.

Here is an example of the softly clipped audio that the Tube Screamer delivers to the amp input.

Reversing the disassembly procedure is all we need to do to get this cool little pedal back together again.  We’re done.

Thanks for reading all the way to the bottom!

CONTACT – David Latchaw EE
281-636-8626