DigiTech Screamin’ Blues Pedal Refurb

Jim purchased this used pedal from a national retailer.  It worked at the store but not at home.  He took it back and the national retailer wanted him to buy a new pedal.  Could the Unbrokenstring Crew help?  Check It Out!

This pedal is absolutely mint;  No sign that it had ever been used.  We hooked it up and it was non-functional on internal battery power, but worked perfectly using an external pedal power source.  Well at least the electronics work!

Let’s put a new battery in it.  Oops, when we pulled the battery, this corrosion was all we found.

Everything is made in China, but could we at least use a name-brand battery that wasn’t dented, Mr. National Retailer?

We loosened up the nuts on the jacks and removed the case screws.  Fortunately, the electrolyte did not leak very far.

Here is a view of the top of the circuit board.  We can easily replace the battery clip leads and get this back on the air!

While we’re here, let’s indulge in a little Tech Porn.  The printed circuit assembly is a nice mix of modern surface mount parts and quality film capacitors, with some small electrolytic caps where it makes sense to use them.

The circuit side of the board is uninteresting unless you are into this sort of thing.  Those are some tiny vias!

The red and black wires on the left are the battery leads, which will be de-soldered.  The long potentiometer shafts reach all the way through the top of the unit and out where the user can reach the knobs.

Another view of the top-side printed circuit board assembly.  These battery leads are coming off now.

The battery leads are unsoldered.  This unit was built with high temperature lead-free solder, but poses no problems for rework such as we are doing here.

Meet the new battery clip.  The case of the pedal has been clam-shelled around the circuit board assembly and we’re installing the screws and connector hardware.

The nuts on the jacks are tightened by hand with a socket.  A layer of felt glued to the socket prevents damage to the finish of the pedal.

The knobs press on, no setscrews.

The foot pedal lid was reinstalled and the unit tested fine with the battery.  Moral of the story: Buy name-brand batteries and don’t leave them in the unit and forget about them!

 

Thanks for reading all the way to the end!

CONTACT: David Latchaw  EE

281-636-8626

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